中央研究院物理研究所

研究成果

期刊論文

[1] Lin Cheng-Chieh, Huang Shing-Jong, Wu Pei-Hao, Chen Tzu-Pei, Huang Chih-Ying, Wang Ying-Chiao, Chen Po-Tuan, Gelev Vladimir, Sankar Raman, Chen Chun-Wei, Yu Tsyr-Yan, accepted, “Direct Investigation of the Reorientational Dynamics of A-site Cations in 2D Organic-Inorganic Hybrid Perovskite by Solid-State NMR”, NATURE. (SCIE) (IF: 69.504; SCI ranking: 1.4%)
[2] Tiwari Ajay, Kakarla D. Chandrasekhar, Lu C. E., Dwivedi G. D., P. C Sreeparvathy, Hsu Chia-Hsiu, Chuang F. C., Puri Nidhi, Hu Y.-J., Lin J.-Y., Murali Suganya, Sankar R., Joshi Aprajita, Saha Surajit, Dhanasekhar C., Kumawat S. M., Chou H., Huang C.-L., Yang H. D., 2024, “Modulation of magnetic and multiferroic properties by chemical substitution in Fe2(MoO4 )3”, Physical Review B, 110(21), 214413-1-214413-10. (SCIE) (IF: 3.7; SCI ranking: 45.6%,31.3%,35.3%)
[3] Chan Yao-Jui, Faizanuddin Syed Mohammed, Kalaivanan Raju, Raman SankarL201118-1, Lin Hsin, Kar Uddipta, Singh Akhilesh Kr., Lee Wei-Li, Vankayala Ranganayakulu K., Ou Min-Nan, Wen Yu-Chieh, 2024, “Origin of nonlinear photocurrents in chiral multifold semimetal CoSi unveiled by terahertz emission spectroscopy”, Physical Review B, 110(20), L201118-1-L201118-7. (SCIE) (IF: 3.7; SCI ranking: 45.6%,31.3%,35.3%)
[4] J Arneth*, K-Y Choi, R Kalaivanan, R Sankar, R Klingeler*, 2024, “Signatures of a Quantum Critical Endpoint in the Kitaev Candidate Na2Co2TeO6”, PHYSICAL REVIEW B, 110(14), L140402-1-L140402-6.
[5] Bayikadi Khasim Saheb, Imam Safdar, Tee Wei-Shen, Kavirajan Sugumaran, Chang Chiao-Yu*, Sabbah Amr, Fu Fang-Yu, Liu Ting-Ran, Chiang Ching-Yu, Shukla Dinesh, Wu Chien-Ting, Chen Li-Chyong, Chou Mei-Yin, Chen Kuei-Hsien, Sankar Raman*, 2024, “Ultra-low lattice thermal conductivity driven high thermoelectric figure of merit in Sb/W co-doped GeTe”, Journal of Materials Chemistry A, 12(44), 30892-30905. (SCIE) (IF: 11.9; SCI ranking: 14.9%,9.1%,9.3%)
[6] Raman Rajesh*, I. B. Shameem Banu, Sankar Raman, Moovendran Kalimuthu, 2024, “Magnetocaloric Analysis of Novel Polycrystalline Sm0.5Sr0.4Nd0.1Mn1‐xTixO3(0≤x≤0.2) that Correlates Structural and Magnetic Properties”, EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, 27(26), e202400230-1-e202400230-12. (SCIE) (IF: 2.3; SCI ranking: 50%)
[7] Duncan Miertschin, Thinh Nguyen, Shalika R Bhandari, Kyryl Shtefiienko, Cole Phillips, Birendra A Magar, Raman Sankar, David E Graf, Keshav Shrestha*, 2024, “Anisotropic quantum transport in ZrSiS probed by high-field torque magnetometry”, PHYSICAL REVIEW B, 110(8), 085140-1-085140-8.
[8] Deepu Kumar, Nguyen The Hoang, Yumin Sim, Youngsu Choi, Kalaivanan Raju, Rajesh Kumar Ulaganathan, Raman Sankar, Maeng-Je Seong*, and Kwang-Yong Choi*, 2024, “Interplay between magnetic and lattice excitations and emergent multiple phase transitions in MnPSe3−x⁢Sx”, PHYSICAL REVIEW B, 110(6), 064414-1-064414-12.
[9] Frank Y Gao, Xinyue Peng, Xinle Cheng, Emil Viñas Boström, Dong Seob Kim, Ravish K Jain, Deepak Vishnu, Kalaivanan Raju, Raman Sankar, Shang-Fan Lee, Michael A Sentef, Takashi Kurumaji, Xiaoqin Li, Peizhe Tang, Angel Rubio*, Edoardo Baldini*, 2024, “Giant chiral magnetoelectric oscillations in a van der Waals multiferroic”, NATURE, 632, 273-279.
[10] Je‐Ho Lee, Seungyeol Lee, Youngsu Choi, Lukas Gries, Rüdiger Klingeler*, Kalaivanan Raju, Rajesh Kumar Ulaganathan, Raman Sankar*, Maeng‐Je Seong*, Kwang‐Yong Choi*, 2024, “Optical Probe of Magnetic Ordering Structure and Spin-Entangled Excitons in Mn-Substituted NiPS3”, ADVANCED FUNCTIONAL MATERIALS, 34(39), 2405153-1-2405153-9.
[11] J. Khatua, Suheon Lee, Gyungbin Ban, Marc Uhlarz, G. Senthil Murugan, R. Sankar, Kwang-Yong Choi*, and P. Khuntia*, 2024, “Magnetism and spin dynamics of the $S={3 \over 2 }$ frustrated trillium lattice compound K2CrTi(PO4)3”, PHYSICAL REVIEW B, 109(18), 184432-1-184432-14.
[12] R. Kalaivanan, Balaji Venkatesan, B. Dundi Sri Chandana, Rajesh Kumar Ulaganathan, G. Senthil Murugan, K. Moovendaran, Joydev Khatua, Li-Hsin Su, W. Zhou, Xiaofeng Xu, Chia-Seng Chang, Tien-Ming Chuang, Yoshiyuki Iizuka, I. Panneer Muthuselvam*, Horng-Tay Jeng*, Kwang-Yong Choi*, and Raman Sankar*, 2024, “Structural, magnetic, and electronic properties of a GdAsSe single crystal: Experimental and theoretical studies”, PHYSICAL REVIEW B, 109(18), 184420-1-184420-11.
[13] Paylaga Naomi Tabudlong, Chou Chang-Ti, Lin Chia-Chun, Taniguchi Takashi, Watanabe Kenji, Sankar Raman, Chan Yang-hao, Chen Shao-Yu, Wang Wei-Hua, 2024, “Monolayer indium selenide: an indirect bandgap material exhibits efficient brightening of dark excitons”, npj 2D Materials and Applications, 8(1), 1-9. (SCIE) (IF: 9.7; SCI ranking: 14.2%,23.1%,11.9%)
[14] Krishnamoorthy Vimal, Bangolla Hemanth Kumar, Chen Chi-Yang, Huang Yu-Ting, Cheng Cheng-Maw, Ulaganathan Rajesh Kumar, Sankar Raman, Lee Kuei-Yi, Du He-Yun, Chen Li-Chyong, Chen Kuei-Hsieh, Chen Ruei-San, 2024, “Efficient Hydrogen Evolution Reaction in 2H-MoS2 Basal Planes Enhanced by Surface Electron Accumulation”, Catalysts, 14(1), 50. (SCIE) (IF: 4.501; SCI ranking: 43%)
[15] D'Olimpio Gianluca, Zhang Yanxue, Rosmus Marcin, Nappini Silvia, Chakraborty Atasi, Olszowska Natalia, Ottaviano Luca, Sankar Raman, Agarwal Amit, Bondino Federica, Gao Junfeng, Politano Antonio, 2024, “Insights into the Stability and Surface Termination of Topological Semimetal NbAs2”, Advanced Materials Interfaces, 2300810, 0. (SCIE) (IF: 6.389; SCI ranking: 26.7%,27.5%)
[16] Yi Liu, Chun-Qiang Xu, Wen-He Jiao, Ping-Gen Cai, Bin Li, Wei Zhou, Bin Qian, Xue-Fan Jiang, Raman Sankar, Xiang-Lin Ke, Guang-Han Cao, Xiao-Feng Xu, 2023, “Correction to:Anisotropic transport in a possible quasi-one-dimensional topological candidate: TaNi2Te3”, Tungsten, 5(4), 609-609.
[17] Lee Yi-Te, Huang Yu-Ting, Chiu Shao-Pin, Wang Ruey-Tay, Taniguchi Takashi, Watanabe Kenji, Sankar Raman, Liang Chi-Te, Wang Wei-Hua*, Yeh Sheng-Shiuan*, Lin Juhn-Jong, 2023, “Determining the Electron Scattering from Interfacial Coulomb Scatterers in Two-Dimensional Transistors”, ACS Applied Materials & Interfaces, 16(1), 1066-1073.
[18] Chazarin Ulysse, Lezoualc'h Mahé, Chou Jyh‐Ping, Pai Woei Wu*, Karn Abhishek, Sankar Raman, Chacon Cyril C., Girard Yann, Repain Vincent, Bellec Amandine, Rousset Sylvie, Smogunov Alexander, Dappe Yannick J., Lagoute Jérôme, 2023, “Formation of Monolayer Charge Density Waves and Anomalous Edge Doping in Na Doped Bulk VSe2”, ADVANCED MATERIALS INTERFACES, 10(3), 2201680. (SCIE) (IF: 6.389; SCI ranking: 26.7%,27.5%)
[19] Pal Sudip, Bahera Prakash, Sahu S.R., Srivastava Himanshu, Srivastava A.K., Lalla N.P., Sankar Raman, Banerjee A., Roy S.B., 2023, “Charge density wave and superconductivity in 6R-TaS2”, Physica B: Condensed Matter, 669, 415266. (SCIE) (IF: 2.988; SCI ranking: 52.2%)
[20] Bangolla Hemanth Kumar, Yusuf Fakhri Muhammad, Lin Ching-Hsuan, Cheng Cheng-Maw, Lu Yi-Hung, Fu Tsu-Yi, Selvarasu Pushpa, Ulaganathan Rajesh Kumar, Sankar Raman, Chen Ruei-San, 2023, “Electrical and optoelectronic anisotropy and surface electron accumulation in ReS2 nanostructures”, NANOSCALE, 15(48), 19735-19745. (SCIE) (IF: 6.7; SCI ranking: 24.2%,24.1%,34.3%,16.9%)
[21] Chih‐Ying Huang, Hung‐Min Lin, Chun‐Hao Chiang, Hsin‐An Chen, Ting‐Ran Liu, Deepak Vishnu S. K, Jau‐Wern Chiou, Raman Sankar, Huang‐Ming Tsai, Way‐Faung Pong, Chun‐Wei Chen, 2023, “Manipulating Spin Exchange Interactions and Spin‐Selected Electron Transfers of 2D Metal Phosphorus Trisulfide Crystals for Efficient Oxygen Evolution Reaction”, Advanced Functional Materials, 33, 43-2305792.
[22] Tamalampudi Srinivasa Reddy, Villegas Juan Esteban, Dushaq Ghada, Sankar Raman, Paredes Bruna, Rasras Mahmoud*, 2023, “High‐Speed Waveguide‐Integrated InSe Photodetector on SiN Photonics for Near‐Infrared Applications”, Advanced Photonics Research, 4(11), 2300162.
[23] Moovendaran Kalimuthu, Kalaivanan Raju, Panneer Muthuselvam I., Rajeesh Kumar N., Lai Yen-Chung, iizuka Yoshiyuki, Choi Kwang-Yong, Sankar Raman*, 2023, “Cluster-glass freezing and antiferromagnetic phase transitions in corundum structure Mg3-Co TeO6”, JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS, 577, 170802. (SCIE) (IF: 3.097; SCI ranking: 59.5%,50.7%)
[24] Bangolla Hemanth Kumar, Lee Yueh-Chien, Shen Wei-Chu, Ulaganathan Rajesh Kumar, Sankar Raman, Du He-Yun, Chen Ruei-San, 2023, “Photoconduction Properties in Tungsten Disulfide Nanostructures”, Nanomaterials, 13(15), 2190. (SCIE) (IF: 5.719; SCI ranking: 30.6%,31.5%,48.2%,23%)
[25] Zhang Yanxue, D'Olimpio Gianluca*, Bondino Federica, Nappini Silvia, Istrate Marian Cosmin, Sankar Raman, Ghica Corneliu, Ottaviano Luca, Gao Junfeng*, Politano Antonio*, 2023, “Surface properties, chemical reactivity, and ambient stability of cadmium diarsenide CdAs<sub>2</sub>, a topological chiral material hosting Kramers-Weyl fermions”, APPLIED SURFACE SCIENCE, 625, 157132. (SCIE) (IF: 6.7; SCI ranking: 26.1%,4.8%,16.9%,22.1%)
[26] Murugan G. Senthil, Lee Chanhyeon, Kalaivanan R., Muthuselvam I. Panneer, Oshima Yugo, Choi Kwang-Yong, Sankar R., 2023, “Anomalous spin dynamics of the $S={3 \over 2 }$ kagome ferromagnet Li9⁢Cr3⁢(P2⁢O7)3⁢(PO4)2”, PHYSICAL REVIEW B, 107(21), 214411. (SCIE) (IF: 3.908; SCI ranking: 47.1%,32.3%,33.3%)
[27] Madhumathy R., Saranya K., Moovendaran K., Ramesh Babu K., Rana Arpita, Choi Kwang-Yong, Kim Heung-Sik, Chen Wei-Tin, Ponmurugan M., Sankar R., Muthuselvam I. Panneer, 2023, “Crystal growth and magnetic properties of the coupled alternating S=1 spin chain Sr2⁢Ni⁢(Se⁢O3)3”, PHYSICAL REVIEW B, 107(21), 214406. (SCIE) (IF: 3.908; SCI ranking: 47.1%,32.3%,33.3%)
[28] Yadav Kanchan, Moovendaran Kalimuthu, Dhenadhayalan Namasivayam, Lee Shan Fang, Leung Man-Kit, Sankar Raman*, 2023, “From Food Toxins to Biomarkers: Multiplexed Detection of Aflatoxin B1 and Aflatoxin M1 in Milk and Human Serum using PEGylated Ternary Transition Metal Sulfides”, Sensors and Actuators Report, 5, 100156.
[29] Ahad Abdul, Gautam K., Majid S. S., Dey K., Tripathy A., Rahman F., Choudhary R. J., Sankar R., Sinha A. K., Kaul S. N., Shukla D. K., 2023, “Random magnetic anisotropy driven transitions in the layered perovskite <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mi>LaSrCoO</mml:mi><mml:mn>4</mml:mn></mml:msub></mml:math>”, PHYSICAL REVIEW B, 107(21), 214405. (SCIE) (IF: 3.908; SCI ranking: 47.1%,32.3%,33.3%)
[30] Srinvasa Reddy Tamalampudi, Juan Esteban Villegas, Ghada Dushaq, Raman Sankar, Bruna Paredes, Mahmoud Rasras, 2023, “A High-Speed Waveguide Integrated InSe Photodetector on SiN Photonics for NIR Applications”, arXiv preprint arXiv:2305.00709, 15, 6.
[31] Mathew Roshan Jesus, Cheng Kai‐Hsiang, Inbaraj Christy Roshini Paul, Sankar Raman, Gao Xuan P.A., Chen Yit‐Tsong, 2023, “An Anti‐Ambipolar Cryo‐Phototransistor”, Advanced Electronic Materials, 2300095, 1-10. (SCIE) (IF: 7.633; SCI ranking: 22.8%,32.7%,16.1%)
[32] Freter Lars, Hsu Hung-Chang, Sankar Raman, Chen Chun-Wei, Dunin-Borkowski Rafal E., Ebert Philipp, Chiu Ya-Ping, Schnedler Michael, 2023, “Interplay of field-induced molecular dipole alignment and compensating surface polarization in low-temperature P-V hysteresis of MAPbBr3⁢(001)”, PHYSICAL REVIEW MATERIALS, 7(5), L052401. (SCIE) (IF: 3.98; SCI ranking: 46.2%)
[33] Paul Inbaraj Christy Roshini, Mathew Roshan Jesus, Sankar Raman, Lin Hsia Yu, Li Nian-Xiu, Chen Yit-Tsong, Chen Yang-Fang, 2023, “Coupling between Pyroelectricity and Built-In Electric Field Enabled Highly Sensitive Infrared Phototransistor Based on InSe/WSe2/P(VDF-TrFE) Heterostructure”, ACS APPLIED MATERIALS & INTERFACES, 15(15), 19121-19128.
[34] Gulo Desman Perdamaian, Hung Nguyen Tuan, Sankar Raman, Saito Riichiro, Liu Hsiang-Lin, 2023, “Exploring optical properties of 2H- and 1T' - MoTe2 single crystals by spectroscopic ellipsometry”, PHYSICAL REVIEW MATERIALS, 7(4), 044001. (SCIE) (IF: 3.4; SCI ranking: 50.6%)
[35] Ghosh Rapti, Papnai Bhartendu, Chen Yu‐Siang, Yadav Kanchan, Sankar Raman, Hsieh Ya‐Ping, Hofmann Mario*, Chen Yang‐Fang*, 2023, “Exciton Manipulation for Enhancing Photoelectrochemical Hydrogen Evolution Reaction in Wrinkled 2D Heterostructures”, Advanced Materials, 35(16), 2210746. (SCIE) (IF: 32.086; SCI ranking: 2.8%,2.4%,2.3%,2.7%,3.1%,2.9%)
[36] Mazzola Federico, Zhang Yanxue, Olszowska Natalia, Rosmus Marcin, D’Olimpio Gianluca, Istrate Marian Cosmin, Politano Grazia Giuseppina, Vobornik Ivana, Sankar Raman, Ghica Corneliu, Gao Junfeng*, Politano Antonio*, 2023, “Fermiology of Chiral Cadmium Diarsenide CdAs2, a Candidate for Hosting Kramers–Weyl Fermions”, The Journal of Physical Chemistry Letters, 14(13), 3120-3125. (SCIE) (IF: 5.7; SCI ranking: 32.3%,28.8%,41.7%,14.3%)
[37] Mazzola Federico, Zhang Yanxue, Olszowska Natalia, Rosmus Marcin, D’Olimpio Gianluca, Istrate Marian Cosmin, Politano Grazia Giuseppina, Vobornik Ivana, Sankar Raman, Ghica Corneliu, Gao Junfeng, Politano Antonio, 2023, “Fermiology of Chiral Cadmium Diarsenide CdAs<sub>2</sub>, a Candidate for Hosting Kramers–Weyl Fermions”, The Journal of Physical Chemistry Letters, 14, 3120-3125. (SCIE) (IF: 6.888; SCI ranking: 27.9%,25.4%,37.3%,13.9%)
[38] Zhang Yanxue, D'Olimpio Gianluca, Bondino Federica, Nappini Silvia, Cosmin Istrate Marian, Sankar Raman, Chica Corneliu, Ottaviano Luca, Gao Junfeng, Politano Antonio, 2023, “Surface properties, chemical reactivity, and ambient stability of cadmium diarsenide CdAs2, a topological chiral material hosting Kramers-Weyl fermions”, Applied Surface Science, 0, 157132. (SCIE) (IF: 7.392; SCI ranking: 25.5%,5%,17.4%,20.3%)
[39] Kim Dong Seob, Huang Di, Guo Chunhao, Li Kejun, Rocca Dario, Gao Frank Y., Choe Jeongheon, Lujan David, Wu Ting‐Hsuan, Lin Kung‐Hsuan, Baldini Edoardo, Yang Li, Sharma Shivani, Kalaivanan Raju, Sankar Raman, Lee Shang‐Fan, Ping Yuan, Li Xiaoqin, 2023, “Anisotropic Excitons Reveal Local Spin Chain Directions in a van der Waals Antiferromagnet”, Advanced Materials, 0, 2206585. (SCIE) (IF: 32.086; SCI ranking: 2.8%,2.4%,2.3%,2.7%,3.1%,2.9%)
[40] Ghosh Rapti, Papnai Bhartendu, Chen Yu‐Siang, Yadav Kanchan, Sankar Raman, Hsieh Ya‐Ping, Hofmann Mario, Chen Yang‐Fang, 2023, “Exciton Manipulation for Enhancing Photo‐electrochemical Hydrogen Evolution Reaction in Wrinkled 2D Heterostructures”, Advanced Materials, 0, 2210746. (SCIE) (IF: 32.086; SCI ranking: 2.8%,2.4%,2.3%,2.7%,3.1%,2.9%)
[41] Ulaganathan Rajesh Kumar, Roy Pradip Kumar, Mhatre Swapnil Milind, Murugesan Raghavan Chinnambedu, Chen Wei‐Liang, Lai Man‐Hong, Subramanian Ambika, Lin Chang‐Yu, Chang Yu‐Ming, Canulescu Stela, Rozhin Alex, Liang Chi‐Te*, Sankar Raman*, 2023, “High‐Performance Photodetector and Angular‐Dependent Random Lasing from Long‐Chain Organic Diammonium Sandwiched 2D Hybrid Perovskite Non‐Linear Optical Single Crystal”, Advanced Functional Materials, 33(17), 2214078. (SCIE) (IF: 19.924; SCI ranking: 5.6%,6.1%,4.9%,7.3%,5%,8.7%)
[42] Li Zi-Yi, Cheng Hao-Yu, Kung Sheng-Hsun, Yao Hsuan-Chun, Inbaraj Christy Roshini Paul, Sankar Raman, Ou Min-Nan, Chen Yang-Fang, Lee Chi-Cheng, Lin Kung-Hsuan, 2023, “Uniaxial Strain Dependence on Angle-Resolved Optical Second Harmonic Generation from a Few Layers of Indium Selenide”, NANOMATERIALS, 13(4), 750. (SCIE) (IF: 5.719; SCI ranking: 30.6%,31.5%,48.2%,23%)
[43] Wu Ting-Hsuan, Cheng Hao-Yu, Lai Wei-Chiao, Sankar Raman, Chang Chia-Seng, Lin Kung-Hsuan, 2023, “Ultrafast carrier dynamics and layer-dependent carrier recombination rate in InSe”, NANOSCALE, 15(7), 3169-3176. (SCIE) (IF: 6.7; SCI ranking: 24.2%,24.1%,34.3%,16.9%)
[44] Krishna Kumar B., Navaneetha Krishnan R., Sankar R., Rukmani R., 2022, “Performance analysis of cognitive wireless retrial queueing networks with admission control for secondary users”, Quality Technology & Quantitative Management, 0, 1-38.
[45] Panneer Muthuselvam I., Madhumathy R., Saranya K., Moovendaran K., Lee Suheon, Choi Kwang-Yong, Chen Wei-tin, Wang Chin-Wei, Chen Peng-Jen, Ponmurugan M., Ou Min-nan, Chen Yang-Yuan, Kim Heung-Sik, Sankar R., 2022, “Spin-singlet ground state of the coupled $Jeff={1 \over 2}$ alternating chain system Sr2⁢Co⁢(SeO3)3”, PHYSICAL REVIEW B, 106(21), 214417. (SCIE) (IF: 3.908; SCI ranking: 47.1%,32.3%,33.3%)
[46] Huang Song-Jeng, Balu Sakthipriya, Barveen Nazar Riswana, Sankar Raman*, 2022, “Surface Engineering of Reduced Graphene Oxide onto the Nanoforest-like Nickel Selenide as a High Performance Electrocatalyst for OER and HER”, Colloids and Surfaces A: Physicochemical and Engineering Aspects, 654, 130024.
[47] Liu Ro-Ya*, Huang Angus, Sankar Raman, Hlevyack Joseph Andrew, Su Chih-Chuan, Weng Shih-Chang, Lin Meng-Kai, Chen Peng, Cheng Cheng-Maw, Denlinger Jonathan D., Mo Sung-Kwan, Fedorov Alexei V., Chang Chia-Seng, Jeng Horng-Tay, Chuang Tien-Ming, Chiang Tai-Chang, 2022, “Dirac Nodal Line in Hourglass Semimetal Nb3SiTe6”, NANO LETTERS, 23(1), 380-388. (SCIE) (IF: 10.8; SCI ranking: 11.8%,17.4%,11.9%,17.6%,10.6%,14.7%)
[48] Takeda Hikaru, Mai Jiancong, Akazawa Masatoshi, Tamura Kyo, Yan Jian, Moovendaran Kalimuthu, Raju Kalaivanan, Sankar Raman, Choi Kwang-Yong, Yamashita Minoru, 2022, “Planar thermal Hall effects in the Kitaev spin liquid candidate Na2Co2TeO6”, Physical Review Research, 4(4), L042035.
[49] A.Sivakumar , Dhas S. Sahaya Jude, A.Saranraj , Sankar Raman, Kumar Raju Suresh, Almansour Abdulrahman I., Kim Ikhyun, Dhas S.A. Martin Britto*, 2022, “Reversible disorder-order type structural phase transition of potassium dihydrogen phosphate bulk single crystals induced by dynamic shock waves”, Physica B: Condensed Matter, 644, 414233. (SCIE) (IF: 2.988; SCI ranking: 52.2%)
[50] Moovendaran Kalimuthu, Kalaivanan Raju, Muthuselvam I. Panneer, Babu K. Ramesh, Lee Suheon, Lee C. H., Bayikadi Khasim Saheb, Dhenadhayalan Namasivayam, Chen Wei-Tin, Wang Chin-Wei, Lai Yen-Chung, iizuka Yoshiyuki, Choi Kwang-Yong, Nalbandyan Vladimir B., Sankar Raman*, 2022, “Triangular Magnet Emergent from Noncentrosymmetric Sr0.94Mn0.86Te1.14O6 Single Crystals”, INORGANIC CHEMISTRY, 61(48), 19058-19066. (SCIE) (IF: 5.436; SCI ranking: 10.9%)
[51] Dutta S.*, Yang L., Liu S.Y., Liu C.M., Liaw L.J., Som S.*, Mohapatra A., Sankar R., Lin W.C*., Chao Y.C.*, 2022, “Impact of Co2+ on the magneto-optical response of MAPbBr3: An inspective study of doping and quantum confinement effect”, MATERIALS TODAY PHYSICS, 27, 100843. (SCIE) (IF: 11.021; SCI ranking: 12.4%,8.7%)
[52] Ghosh Rapti, Kang Yi-Sun, Yadav Kanchan, Lin Hung-I, Yen Zhi Long, Lin Hsia-Yu, Lu Guan Zhang, Sankar Raman, Hsieh Ya-Ping, Hofmann Mario, Chen Yang-Fang*, 2022, “Omnidirectional and Highly Sensitive Microtubular Photodetectors Based on QD/2D Heterojunctions”, ACS APPLIED ELECTRONIC MATERIALS, 4(11), 5208-5214. (SCIE) (IF: 4.494; SCI ranking: 27.7%,38.7%)
[53] Lu Yi-Ying, Yu Hsiao-Ching, Wang You-Xin, Hung Chih-Keng, Chen You-Ren, Jhou Jie, Yen Peter Tsung-Wen, Hsu Jui-Hung, Sankar Raman, 2022, “Optical determination of layered-materials InSe thickness via RGB contrast method and regression analysis”, NANOTECHNOLOGY, 33(48), 485702. (SCIE) (IF: 3.953; SCI ranking: 46.5%,58.2%,31.7%)
[54] Murtaza Tahir, Yang Haiyang, Feng Jiajia, Shen Yi, Ge Yongheng, Liu Yi, Xu Chunqiang, Jiao Wenhe, Lv Yaokang, Ridley Christopher J., Bull Craig L., Biswas Pabitra K., Sankar Raman, Zhou Wei, Qian Bin, Jiang Xuefan, Feng Zhenjie, Zhou Yonghui, Zhu Ziming, Yang Zhaorong, Xu Xiaofeng, 2022, “Cascade of pressure-driven phase transitions in the topological nodal-line superconductor PbTaSe2”, PHYSICAL REVIEW B, 106(6), L060501. (SCIE) (IF: 3.908; SCI ranking: 47.1%,32.3%,33.3%)
[55] Cho Kwanghee, Lee Seungyeol, Kalaivanan Raju, Sankar Raman, Choi Kwang‐Yong, Park Soonyong, 2022, “Tunable Ferroelectricity in Van der Waals Layered Antiferroelectric CuCrP2S6”, Advanced Functional Materials, 32(36), 2204214. (SCIE) (IF: 19.924; SCI ranking: 5.6%,6.1%,4.9%,7.3%,5%,8.7%)
[56] Murugan Ganesan Senthil, Lee Suheon, Wang C., Luetkens H., Choi Kwang-Yong, Sankar Raman, 2022, “Spin dynamics of the one-dimensional double chain spin- ${1 \over 2 }$ antiferromagnet KNaCuP2⁢O7”, Physical Review B, 105(17), 174442. (SCIE) (IF: 3.908; SCI ranking: 47.1%,32.3%,33.3%)
[57] Lin I C, Lee M H, Wu P C, Lin S C, Chen J W, Li C-C, Guo G Y, Chu Y-H, Sankar R, Chu M-W, 2022, “Atomic-scale observation of spontaneous hole doping and concomitant lattice instabilities in strained nickelate films”, NEW JOURNAL OF PHYSICS, 24(2), 023011. (SCIE) (IF: 3.716; SCI ranking: 38.4%)
[58] Sheelam Anjaiah, Balu Sakthipriya, Muneeb Adil, Bayikadi Khasim Saheb, Namasivayam Dhenadhayalan, Siddharthan Erakulan E., Inamdar Arif I., Thapa Ranjit, Chiang Ming-Hsi, Isaac Huang Song-Jeng, Sankar Raman*, 2022, “Improved Oxygen Redox Activity by High-Valent Fe and Co3+ Sites in the Perovskite LaNi1–xFe0.5xCo0.5xO3”, ACS Applied Energy Materials, 5(1), 343-354. (SCIE) (IF: 6.959; SCI ranking: 27.3%,32.8%,24.9%)
[59] Dutta Somrita, Vishnu S. K Deepak, Som Sudipta, Chaurasiya Rajneesh, Patel Dinesh Kumar, Moovendaran Kalimuthu, Lin Cheng-Chieh, Chen Chun-Wei, Sankar Raman*, 2022, “Segmented Highly Reversible Thermochromic Layered Perovskite [(CH2)2(NH3)2]CuCl4 Crystal Coupled with an Inverse Magnetocaloric Effect”, ACS Applied Electronic Materials, 4(1), 521-530. (SCIE) (IF: 4.494; SCI ranking: 27.7%,38.7%)
[60] Bayikadi Khasim Saheb, Imam Safdar, Ubaid Mohammad, Aziz Anver, Chen Kuei-Hsien, Sankar Raman, 2022, “Effect of aliovalent substituted highly disordered GeTe compound's thermoelectric performance”, Journal of Alloys and Compounds, 922, 166221. (SCIE) (IF: 6.371; SCI ranking: 31.5%,27.7%,6.3%)
[61] Lu Yi-Ying, Huang Yan-Ting, Chen Jia-Ni, Jhou Jie, Lan Liang-Wei, Kuo Chien-Cheng, Hsu Jui-Hung, Hsieh Shang-Hsien, Chen Chia-Hao, Sankar Raman, 2022, “Energy Barrier at Indium/Indium Selenide Nanosheet Interfaces: Implications of Metal-to-Insulator Transition for Field-Effect Transistor Modeling”, ACS Applied Nano Materials, 5(2), 1911-1916. (SCIE) (IF: 6.14; SCI ranking: 29.2%,41.8%)
[62] Harsh Rishav, Mondal Sourav, Sharma Devina, Bouatou Mehdi, Chacon Cyril, Ilyn Maxim, Rogero Celia, Repain Vincent, Bellec Amandine, Girard Yann, Rousset Sylvie, Sankar Raman, Pai Woei Wu, Narasimhan Shobhana, Lagoute Jérôme, 2022, “Identification and Manipulation of Defects in Black Phosphorus”, The Journal of Physical Chemistry Letters, 13(27), 6276-6282. (SCIE) (IF: 6.888; SCI ranking: 27.9%,25.4%,37.3%,13.9%)
[63] Wyzula Jan, Lu Xin, Santos‐Cottin David, Mukherjee Dibya Kanti, Mohelský Ivan, Le Mardelé Florian, Novák Jiří, Novak Mario, Sankar Raman, Krupko Yuriy, Piot Benjamin A., Lee Wei‐Li, Akrap Ana, Potemski Marek, Goerbig Mark O., Orlita Milan, 2022, “Lorentz‐Boost‐Driven Magneto‐Optics in a Dirac Nodal‐Line Semimetal”, Advanced Science, 0, 2105720. (SCIE) (IF: 17.521; SCI ranking: 7.8%,6.1%,10.9%)
[64] Howard Sean, Raghavan Arjun, Iaia Davide, Xu Caizhi, Flötotto David, Wong Man-Hong, Mo Sung-Kwan, Singh Bahadur, Sankar Raman, Lin Hsin, Chiang Tai-Chang, Madhavan Vidya, 2022, “Observation of a smoothly tunable Dirac point in Ge⁢(Bi”, Physical Review Materials, 6(4), 044201. (SCIE) (IF: 3.98; SCI ranking: 46.2%)
[65] Cheng Chih-Yi, Pai Wei-Liang, Chen Yi-Hsun, Paylaga Naomi Tabudlong, Wu Pin-Yun, Chen Chun-Wei, Liang Chi-Te, Chou Fang-Cheng, Sankar Raman, Fuhrer Michael S., Chen Shao-Yu, Wang Wei-Hua, 2022, “Phase Modulation of Self-Gating in Ionic Liquid-Functionalized InSe Field-Effect Transistors”, Nano Letters, 22(6), 2270-2276. (SCIE) (IF: 12.262; SCI ranking: 11.1%,15.2%,9.2%,15.5%,8.1%,14.5%)
[66] Inamdar Arif I., Sainbileg Batjargal, Lin Chi-Jia, Usman Muhammad, Kamal Saqib, Chiou Kuan-Ru, Pathak Abhishek, Luo Tzuoo-Tsair, Bayikadi Khasim Saheb, Sankar Raman, Chen Jenq-Wei, Tseng Tien-Wen, Chen Ruei-San, Hayashi Michitoshi, Chiang Ming-Hsi, Lu Kuang-Lieh, 2022, “Regimented Charge Transport Phenomena in Semiconductive Self-Assembled Rhenium Nanotubes”, ACS Applied Materials & Interfaces, 14(10), 12423-12433.
[67] Blue Brandon T., Lough Stephanie D., Le Duy, Thompson Jesse E., Rahman Talat S., Sankar R., Ishigami Masahiro, 2022, “Scanning tunneling microscopy and spectroscopy of NiTe2”, Surface Science, 722, 122099. (SCIE) (IF: 2.07; SCI ranking: 78.8%,63.8%)
[68] Govindaraj L., Arumugam S., Thiyagarajan R., Kumar Dinesh, Kannan M., Das Dhruba, Suraj T.S., Sankaranarayanan V., Sethupathi K., Baskaran G., Sankar Raman, Rao M.S.Ramachandra, 2022, “Wohlleben Effect and Emergent π junctions in superconducting Boron doped Diamond thin films”, Physica C: Superconductivity and its Applications, 598, 1354065. (SCIE) (IF: 1.534; SCI ranking: 78.9%,78.3%)
[69] Paul Inbaraj Christy Roshini, Mathew Roshan Jesus, Ulaganathan Rajesh Kumar, Sankar Raman, Kataria Monika, Lin Hsia Yu, Chen Yit-Tsong, Hofmann Mario, Lee Chih-Hao, Chen Yang-Fang, 2021, “A Bi-Anti-Ambipolar Field Effect Transistor”, ACS Nano, 15(5), 8686-8693. (SCIE) (IF: 18.027; SCI ranking: 7.2%,7.3%,5.8%,10%)
[70] Imam Safdar, Bayikadi Khasim Saheb, Ubaid Mohammad, Ranganayakulu V.K., Devi Sumangala, Pujari Bhalchandra S., Chen Yang-Yuan, Chen Li-Chyong, Chen Kuei-Hsien, Lin Feng-Li, Sankar Raman, 2021, “Achieving synergistic performance through highly compacted microcrystalline rods induced in Mo doped GeTe based compounds”, Materials Today Physics, 17, 100571. (SCIE) (IF: 11.021; SCI ranking: 12.4%,8.7%)
[71] Liu Yi, Xu Chun-Qiang, Jiao Wen-He, Cai Ping-Gen, Li Bin, Zhou Wei, Qian Bin, Jiang Xue-Fan, R Kalaivaman, Sankar Raman, Ke Xiang-Lin, Cao Guang-Han, Xu Xiao-Feng, 2021, “Anisotropic transport in a possible quasi-one-dimensional topological candidate: TaNi2Te3”, Tungsten, 1, 7.
[72] Lee Seungyeol, Park Jaena, Choi Youngsu, Raju Kalaivanan, Chen Wei-Tin, Sankar Raman, Choi Kwang-Yong, 2021, “Chemical tuning of magnetic anisotropy and correlations in Ni1−xFexPS3”, Physical Review B, 104(17), 174412. (SCIE) (IF: 3.908; SCI ranking: 47.1%,32.3%,33.3%)
[73] Karna Sunil K., Wang C. W., Sankar R., Temple D., Avdeev M., 2021, “Commensurate and incommensurate magnetic structure of the moderately frustrated antiferromagnet Li2M(WO4)2 with M=Co,Ni”, Physical Review B, 104(13), 134435. (SCIE) (IF: 3.908; SCI ranking: 47.1%,32.3%,33.3%)
[74] Yen Yun, Chiu Cheng-Li, Lin Ping-Hui, Sankar Raman, Chuang Tien-Ming, Guo Guang-Yu, 2021, “Dirac nodal line and Rashba spin-split surface states in nonsymmorphic ZrGeTe”, New Journal of Physics, 23(10), 103019. (SCIE) (IF: 3.716; SCI ranking: 38.4%)
[75] Glamazda A., Sharafeev A., Bohle R., Lemmens P., Choi K.-Y., Chou F. C., Sankar R., 2021, “Doping from CDW to topological superconductivity: The role of defects on phonon scattering in the non-centrosymmetric PbxTaSe2”, Low Temperature Physics, 47(11), 912-919. (SCIE) (IF: 0.891; SCI ranking: 91.9%)
[76] Lu Yi-Ying, Peng Yu-Ting, Huang Yan-Ting, Chen Jia-Ni, Jhou Jie, Lan Liang-Wei, Jian Shi-Hao, Kuo Chien-Cheng, Hsieh Shang-Hsien, Chen Chia-Hao, Sankar Raman, Chou Fang-Cheng, 2021, “Engineering an Indium Selenide van der Waals Interface for Multilevel Charge Storage”, ACS Applied Materials & Interfaces, 13(3), 4618-4625. (SCIE) (IF: 10.383; SCI ranking: 14.2%,20.9%)
[77] Wang Xiao, Hu Zhiwei, Agrestini Stefano, Herrero-Martín Javier, Valvidares Manuel, Sankar Raman, Chou Fang-Cheng, Chu Ying-Hao, Tanaka Arata, Tjeng Liu Hao, Pellegrin Eric, 2021, “Evidence for largest room temperature magnetic signal from Co2+ in antiphase-free & fully inverted CoFe2O4 in multiferroic-ferrimagnetic BiFeO3-CoFe2O4 nanopillar thin films”, Journal of Magnetism and Magnetic Materials, 530, 167940. (SCIE) (IF: 3.097; SCI ranking: 59.5%,50.7%)
[78] Panneer Muthuselvam I., Saranya K., Büscher Florian, Wulferding Dirk, Lemmens Peter, Chen Wei-tin, Sankar R., 2021, “High magnetic anisotropy and magnon excitations in single crystals of the double spin chain compound PbMn2Ni6Te3O18”, Physical Review B, 103(6), 064401. (SCIE) (IF: 3.908; SCI ranking: 47.1%,32.3%,33.3%)
[79] Lingannan Govindaraj, Ganesan Kalaiselvan, Mariappan Sathiskumar, Sankar Raman, Uwatoko Y., Arumugam S., 2021, “Internal and External Pressure Effects on Superconductivity in FeTexSe1-x (x = 0.46, 0.54) Single Crystals”, Journal of Superconductivity and Novel Magnetism, 34(3), 725-731. (SCIE) (IF: 1.675; SCI ranking: 75.2%,75.4%)
[80] Shrestha K, Miertschin D, Sankar R, Lorenz B, Chu C W, 2021, “Large magnetoresistance and quantum oscillations in Sn0.05Pb0.95Te”, Journal of Physics: Condensed Matter, 33(33), 335501.
[81] Murugan G. Senthil, Babu K. Ramesh, Sankar R., Chen W. T., Muthuselvam I. Panneer, Chattopadhyay Sumanta, Choi K.-Y., 2021, “Magnetic and structural dimer networks in layered K2Ni(MoO4)2”, Physical Review B, 103(2), 024451. (SCIE) (IF: 3.908; SCI ranking: 47.1%,32.3%,33.3%)
[82] Murtaza Tahir, Kalaivanan Raju, Madeswaran G., Bayikadi Khasimsaheb, Sankar Raman, 2021, “Magnetic properties of honeycomb spin lattice compounds Na2M2TeO6 (M = Co, Ni) and spin dimer compound Na2Cu2TeO6 single crystals by flux-growth”, Journal of Materials Research and Technology, 14, 1601-1608.
[83] Muthuselvam I. Panneer, Saranya K., Kasinathan Deepa, Bhowmik R. N., Sankar R., Dhenadhayalan Namasivayam, Shu G. J., Chen Wei-tin, Kavitha L., Lin King-Chuen, 2021, “Magnetic spin order in the honeycomb structured Pb6Co9(TeO6)5 compound”, Physical Review B, 104(17), 174442. (SCIE) (IF: 3.908; SCI ranking: 47.1%,32.3%,33.3%)
[84] Lee C. H., Lee S., Choi Y. S., Jang Z. H., Kalaivanan R., Sankar R., Choi K.-Y., 2021, “Multistage development of anisotropic magnetic correlations in the Co-based honeycomb lattice Na2Co2TeO6”, Physical Review B, 103(21), 214447. (SCIE) (IF: 3.908; SCI ranking: 47.1%,32.3%,33.3%)
[85] Ebad-Allah J., Rojewski S., Vöst M., Eickerling G., Scherer W., Uykur E., Sankar Raman, Varrassi L., Franchini C., Ahn K.-H., Kuneš J., Kuntscher C. A., 2021, “Pressure-Induced Excitations in the Out-of-Plane Optical Response of the Nodal-Line Semimetal ZrSiS”, Physical Review Letters, 127(7), 076402. (SCIE) (IF: 9.185; SCI ranking: 9.3%)
[86] Cui Hengbo, Yun Seohee, Lee Kyeong Jun, Lee Chanhyeon, Chang Seo Hyoung, Lee Yongjae, Lee Hyun Hwi, Raju Kalaivanan, Moovendaran Kalimuthu, Sankar Raman, Choi Kwang-Yong, 2021, “Quasihydrostatic versus nonhydrostatic pressure effects on the electrical properties of NiPS3”, Physical Review Materials, 5(12), 124008. (SCIE) (IF: 3.98; SCI ranking: 46.2%)
[87] Rajput Nitul S., Baik Hionsuck, Lu Jin-You, Tamalampudi Srinivasa Reddy, Sankar Raman, Al Ghaferi Amal, Chiesa Matteo, 2021, “Revealing the Quasi-Periodic Crystallographic Structure of Self-Assembled SnTiS3 Misfit Compound”, The Journal of Physical Chemistry C, 125(18), 9956-9964. (SCIE) (IF: 4.177; SCI ranking: 47.3%,41.3%,56.4%)
[88] Multer Daniel, Yin Jia-Xin, Zhang Songtian S., Zheng Hao, Chang Tay-Rong, Bian Guang, Sankar Raman, Hasan M. Zahid, 2021, “Robust topological state against magnetic impurities observed in the superconductor PbTaSe2”, Physical Review B, 104(7), 075145. (SCIE) (IF: 3.908; SCI ranking: 47.1%,32.3%,33.3%)
[89] Lin Chang-Yu, Ulaganathan Rajesh Kumar, Sankar Raman, Murugesan Raghavan Chinnambedu, Subramanian Ambika, Rozhin Alex, Firdoz Shaik, 2021, “Silicon-based two-dimensional chalcogenide of p-type semiconducting silicon telluride nanosheets for ultrahigh sensitive photodetector applications”, Journal of Materials Chemistry C, 9(32), 10478-10486. (SCIE) (IF: 8.067; SCI ranking: 20.5%,14.9%)
[90] Ulaganathan Rajesh Kumar, Murugesan Raghavan Chinnambedu, Lin Chang‐Yu, Subramanian Ambika, Chen Wei‐Liang, Chang Yu‐Ming, Rozhin Alex, Sankar Raman, 2021, “Stable Formamidinium‐Based Centimeter Long Two‐Dimensional Lead Halide Perovskite Single‐Crystal for Long‐Live Optoelectronic Applications”, Advanced Functional Materials, 31, 2112277. (SCIE) (IF: 19.924; SCI ranking: 5.6%,6.1%,4.9%,7.3%,5%,8.7%)
[91] Majchrzak Paulina, Pakdel Sahar, Biswas Deepnarayan, Jones Alfred J. H., Volckaert Klara, Marković Igor, Andreatta Federico, Sankar Raman, Jozwiak Chris, Rotenberg Eli, Bostwick Aaron, Sanders Charlotte E., Zhang Yu, Karras Gabriel, Chapman Richard T., Wyatt Adam, Springate Emma, Miwa Jill A., Hofmann Philip, King Phil D. C., Lanatà Nicola, Chang Young Jun, Ulstrup Søren, 2021, “Switching of the electron-phonon interaction in 1T−VSe2 assisted by hot carriers”, Physical Review B, 103(24), L241108. (SCIE) (IF: 3.908; SCI ranking: 47.1%,32.3%,33.3%)
[92] Huang Song-Jeng, Muneeb Adil, Sabhapathy Palani, Sheelam Anji, Bayikadi Khasim Saheb, Sankar Raman, 2021, “Tailoring the Co4+/Co3+ active sites in a single perovskite as a bifunctional catalyst for the oxygen electrode reactions”, Dalton Transactions, 50(21), 7212-7222. (SCIE) (IF: 4.569; SCI ranking: 15.2%)
[93] Huang Song Jeng, Muneeb Adil, Abbas Aqeel, Sankar Raman, 2021, “The effect of Mg content and milling time on the solid solubility and microstructure of Ti–Mg alloys processed by mechanical milling”, Journal of Materials Research and Technology, 11, 1424-1433.
[94] Huang Song-Jeng, Muneeb Adil, Sabhapathy Palani, Bayikadi Khasim Saheb, Murtaza Tahir, Raju Kalaivanan, Chen Li-Chyong, Chen Kuei-Hsien, Sankar Raman, 2021, “Two-Dimensional Layered NiLiP2S6 Crystals as an Efficient Bifunctional Electrocatalyst for Overall Water Splitting”, Catalysts, 11(7), 786. (SCIE) (IF: 4.501; SCI ranking: 43%)
[95] Inamdar Arif I., Sainbileg Batjargal, Kamal Saqib, Bayikadi Khasim Saheb, Sankar Raman, Luo Tzuoo Tsair, Hayashi Michitoshi, Chiang Ming-Hsi, Lu Kuang-Lieh, 2021, “Water-assisted spin-flop antiferromagnetic behaviour of hydrophobic Cu-based metal–organic frameworks”, Dalton Transactions, 50(17), 5754-5758. (SCIE) (IF: 4.569; SCI ranking: 15.2%)
[96] H-C Chang, T-H Chen, R Sankar, Y-J Yang, L-C Chen, K-H Chen, 2020, “Highly improved thermoelectric performance of BiCuTeO achieved by decreasing the oxygen content”, Materials Today Physics, 15,100248. (SCIE) (IF: 11.021; SCI ranking: 12.4%,8.7%)
[97] Rojin Varghese, V Shobin Vijay, S Rajesh, A Sakunthala, P Senthil Kumar, Raman Sankar, 2020, “Thin film LiV3O8 nanorod formation through Pulsed Laser Deposition and the effect of heat treatment”, Vacuum, 182,109722. (SCIE) (IF: 4.11; SCI ranking: 42.8%,29.8%)
[98] RS Ravi Sankar, Bankuru Vamsi, KK Deepika, P Ramesh, 2020, “Flexible Power Regulation Of Hvdc Light System”, Solid State Technology, 63 No. 6 (2020).
[99] Yi-Ying Lu, Chuan-Ruei Guo, Hui-Lin Yeh, He-Wen Chen, Chien-Cheng Kuo, Jui-Hung Hsu, Jie Jhou, Yan-Ting Huang, Shang-Hsien Hsieh, Chia-Hao Chen, Ching-Hwa Ho, Raman Sankar, Fang-Cheng Chou, 2020, “Multilayer GaSe/InSe Heterointerface-Based Devices for Charge Transport and Optoelectronics”, ACS Applied Nano Materials, 2020, XXXX, XXX, XXX-XXX. (SCIE) (IF: 6.14; SCI ranking: 29.2%,41.8%)
[100] Anjaiah Sheelam, Raman Sankar, 2020, “Carbon-supported cobalt (III) complex for direct reduction of oxygen in alkaline medium”, International Journal of Hydrogen Energy, 45,24738-24748. (SCIE) (IF: 7.139; SCI ranking: 26.1%,26.7%,31.9%)
[101] Arvind Shankar Kumar, Kasun Premasiri, Min Gao, U Rajesh Kumar, Raman Sankar, Fang-Cheng Chou, Xuan PA Gao, 2020, “Electron-electron interactions in the two-dimensional semiconductor InSe”, American Physical Society, 102, 121301(R).
[102] I Panneer Muthuselvam, K Saranya, R Sankar, RN Bhowmik, L Kavitha, 2020, “Experimental study of multiple magnetic transitions in micrometer and nano-grain sized Ni3TeO6-type oxide”, Journal of Applied Physics, 128, 123902. (SCIE) (IF: 2.877; SCI ranking: 46%)
[103] Raman Sankar, I Panneer Muthuselvam, Karthik Rajagopal, K Ramesh Babu, G Senthil Murugan, Khasim Saheb Bayikadi, K Moovendaran, Chien Ting Wu, Guang-Yu Guo, 2020, “Anisotropic Magnetic Properties of Nonsymmorphic Semimetallic Single Crystal NdSbTe”, Crystal Growth & Design, 20, 10, 6585–6591. (SCIE) (IF: 4.01; SCI ranking: 42.2%,19.2%,44.8%)
[104] Chunqiang Xu, Yi Liu, Pinggen Cai, Bin Li, Wenhe Jiao, Yunlong Li, Junyi Zhang, Wei Zhou, Bin Qian, Xuefan Jiang, Zhixiang Shi, Raman Sankar, Jinglei Zhang, Feng Yang, Zengwei Zhu, Pabitra Biswas, Dong Qian, Xianglin Ke, Xiaofeng Xu, 2020, “Anisotropic Transport and Quantum Oscillations in the Quasi-One-Dimensional TaNiTe5: Evidence for the Nontrivial Band Topology”, The Journal of Physical Chemistry Letters, 11, 18, 7782–7789. (SCIE) (IF: 6.888; SCI ranking: 27.9%,25.4%,37.3%,13.9%)
[105] Tian Le, Yue Sun, Hui-Ke Jin, Liqiang Che, Lichang Yin, Jie Li, Guiming Pang, Chunqiang Xu, Lingxiao Zhao, Shunichiro Kittaka, Toshiro Sakakibara, Kazushige Machida, Raman Sankar, Huiqiu Yuan, Genfu Chen, Xiaofeng Xu, Shiyan Li, Yi Zhou, Xin Lu, 2020, “Evidence for nematic superconductivity of topological surface states in PbTaSe2”, SCIENCE BULLETIN, 16, 1349-1355. (SCIE) (IF: 20.577; SCI ranking: 6.8%)
[106] Christy Roshini Paul Inbaraj, Roshan Jesus Mathew, Raman Sankar, Chih-Hao Lee, Yang-Fang Chen, 2020, “Doping Engineered InSe Flakes for High Mobility Phototransistor”, Novel Optical Materials and Applications, 978-1-943580-79-8.
[107] Yue Sun, Shunichiro Kittaka, Toshiro Sakakibara, Kazushige Machida, R Sankar, Xiaofeng Xu, Nan Zhou, Xiangzhuo Xing, Zhixiang Shi, Sunseng Pyon, Tsuyoshi Tamegai, 2020, “Fully gapped superconductivity without sign reversal in the topological superconductor PbTaSe 2”, Physical Review B, 102, 024517. (SCIE) (IF: 3.908; SCI ranking: 47.1%,32.3%,33.3%)
[108] Srinivasa Reddy Tamalampudi, Jin-You Lu, Nitul Rajput, Chia-Yun Lai, Boulos Alfakes, Raman Sankar, Harry Apostoleris, Shashikant P Patole, Ibraheem Almansouri, Matteo Chiesa, 2020, “Superposition of semiconductor and semi-metal properties of self-assembled 2D SnTiS 3 heterostructures”, 2D Materials and Applications, 4:23.
[109] Pradip Kumar Roy, Rajesh Kumar Ulaganathan, Chinnambedu Murugesan Raghavan, Swapnil Milind Mhatre, Hung-I Lin, Wei-Liang Chen, Yu-Ming Chang, Alex Rozhin, Yun-Tzu Hsu, Yang-Fang Chen, Raman Sankar, Fang-Cheng Chou, Chi-Te Liang, 2020, “Unprecedented random lasing in 2D organolead halide single-crystalline perovskite microrods”, NANOSCALE, 12, 18269-18277. (SCIE) (IF: 8.307; SCI ranking: 20.6%,20.2%,28.2%,14.3%)
[110] Tien-Tien Yeh, Chien-Ming Tu, Wen-Hao Lin, Cheng-Maw Cheng, Wen-Yen Tzeng, Chen-Yu Chang, Hideto Shirai, Takao Fuji, Raman Sankar, Fang-Cheng Chou, Marin M Gospodinov, Takayoshi Kobayashi , Chih-Wei Luo, 2020, “Femtosecond time-evolution of mid-infrared spectral line shapes of Dirac fermions in topological insulators”, SCIENTIFIC REPORTS, 10, 9803. (SCIE) (IF: 4.997; SCI ranking: 25.7%)
[111] Anjaiah Sheelam, Adil Muneeb, Biva Talukdar, Rini Ravindranath, Song-Jeng Huang, Chun-Hong Kuo, Raman Sankar, 2020, “Flexible and free-standing polyvinyl alcohol-reduced graphene oxide-Cu 2 O/CuO thin films for electrochemical reduction of carbon dioxide”, Journal of Applied Electrochemistry, 50, pages979–991. (SCIE) (IF: 2.925; SCI ranking: 73.3%)
[112] K Gautam, SS Majid, S Francoual, A Ahad, K Dey, MC Rahn, R Sankar, FC Chou, DK Shukla, 2020, “Magnetic and orbital correlations in multiferroic CaMn 7 O 12 probed by x-ray resonant elastic scattering”, Physical Review B, 101, 224430. (SCIE) (IF: 3.908; SCI ranking: 47.1%,32.3%,33.3%)
[113] Prabu Mani, Anjaiah Sheelam, Pitchiah Esakki Karthik, Raman Sankar, Kothandaraman Ramanujam, Sukhendu Mandal, 2020, “Nickel-Based Hybrid Material for Electrochemical Oxygen Redox Reactions in an Alkaline Medium”, ACS Applied Energy Materials, 3, 7, 6408–6415. (SCIE) (IF: 6.959; SCI ranking: 27.3%,32.8%,24.9%)
[114] Christy Roshini Paul Inbaraj, Roshan Jesus Mathew, Rajesh Kumar Ulaganathan, Raman Sankar, Monika Kataria, Hsia Yu Lin, Hao-Yu Cheng, Kung-Hsuan Lin, Hung-I Lin, Yu-Ming Liao, Fang-Cheng Chou, Yit- Tsong Chen, Chih-Hao Lee, Yang-Fang Chen, 2020, “Modulating charge separation with h-BN mediation in vertical van der Waals heterostructures”, ACS APPLIED MATERIALS & INTERFACES, 12,26213–26221. (SCIE) (IF: 10.383; SCI ranking: 14.2%,20.9%)
[115] Sarita Sharma, Khasimsaheb Bayikadi, Raman Sankar, Sonnathi Neeleshwar, 2020, “Synergistic optimization of thermoelectric performance in earth-abundant Cu2ZnSnS4 by inclusion of graphene nanosheets”, NANOTECHNOLOGY, 31 365402. (SCIE) (IF: 3.953; SCI ranking: 46.5%,58.2%,31.7%)
[116] Gaurav Pande, Jyun-Yan Siao, Wei-Liang Chen, Chien-Ju Lee, Raman Sankar, Yu-Ming Chang, Chii-Dong Chen, Wen-Hao Chang, Fang-Cheng Chou, Minn-Tsong Lin, 2020, “Ultralow Schottky Barriers in Hexagonal Boron Nitride-Encapsulated Monolayer WSe2 Tunnel Field-Effect Transistors”, ACS APPLIED MATERIALS & INTERFACES, 12,18667–18673. (SCIE) (IF: 10.383; SCI ranking: 14.2%,20.9%)
[117] Songtian S Zhang, Jia-Xin Yin, Guangyang Dai, Lingxiao Zhao, Tay-Rong Chang, Nana Shumiya, Kun Jiang, Hao Zheng, Guang Bian, Daniel Multer, Maksim Litskevich, Guoqing Chang, Ilya Belopolski, Tyler A Cochran, Xianxin Wu , Desheng Wu, Jianlin Luo, Genfu Chen, Hsin Lin, Fang-Cheng Chou, Xiancheng Wang, Changqing Jin, Raman Sankar, Ziqiang Wang, M Zahid Hasan, 2020, “Field-free platform for Majorana-like zero mode in superconductors with a topological surface state”, PHYSICAL REVIEW B, 101, 100507. (SCIE) (IF: 3.908; SCI ranking: 47.1%,32.3%,33.3%)
[118] Khasim Saheb Bayikadi, Chien Ting Wu, Li-Chyong Chen, Kuei-Hsien Chen, Fang-Cheng Chou, Raman Sankar, 2020, “Synergistic optimization of thermoelectric performance of Sb doped GeTe with a strained domain and domain boundaries”, JOURNAL OF MATERIALS CHEMISTRY A, 8, 5332-5341. (SCIE) (IF: 14.511; SCI ranking: 10.9%,7.6%,7.5%)
[119] Wen-Yen Tzeng, Ya-Hsin Tseng, Tien-Tien Yeh, Chien-Ming Tu, Raman Sankar, Yu-Han Chen, Bang-Hao Huang, Fang-Cheng Chou, and Chih-Wei Luo, 2020, “Selenium nanoparticle prepared by femtosecond laser-induced plasma shock wave”, OPTICS EXPRESS, 28, 685-694. (SCIE) (IF: 3.833; SCI ranking: 27.5%)
[120] Zhang Yanxue, Nappini Silvia, Sankar Raman, Bondino Federica, Gao Junfeng, Politano Antonio, 2020, “Assessing the stability of Cd3As2 Dirac semimetal in humid environments: the influence of defects, steps and surface oxidation”, Journal of Materials Chemistry C, 9(4), 1235-1244. (SCIE) (IF: 8.067; SCI ranking: 20.5%,14.9%)
[121] Wang Chih-Yuan, Lin Yun-Wu, Chuang Chiashain, Yang Cheng-Hsueh, Patel Dinesh K, Chen Sheng-Zong, Yeh Ching-Chen, Chen Wei-Chen, Lin Chia-Chun, Chen Yi-Hsun, Wang Wei-Hua, Sankar Raman, Chou Fang-Cheng, Kruskopf Mattias, Elmquist Randolph E, Liang Chi-Te, 2020, “Magnetotransport in hybrid InSe/monolayer graphene on SiC”, Nanotechnology, 32(15), 155704. (SCIE) (IF: 3.953; SCI ranking: 46.5%,58.2%,31.7%)
[122] Perumal Packiyaraj, Kumar Ulaganathan Rajesh, Sankar Raman, Zhu Ling, 2020, “Staggered band offset induced high performance opto-electronic devices: Atomically thin vertically stacked GaSe-SnS2 van der Waals p-n heterostructures”, Applied Surface Science, 535, 147480. (SCIE) (IF: 7.392; SCI ranking: 25.5%,5%,17.4%,20.3%)
[123] Yi-Hsun Chen, Chih-Yi Cheng, Shao-Yu Chen, Jan Sebastian Dominic Rodriguez, Han-Ting Liao, Kenji Watanabe, Takashi Taniguchi, Chun-Wei Chen, Raman Sankar, Fang-Cheng Chou, Hsiang-Chih Chiu, Wei-Hua Wang, 2019, “Oxidized-monolayer tunneling barrier for strong Fermi-level depinning in layered InSe transistors”, npj 2D materials and applications, 1-1-7. (SCIE) (IF: 10.516; SCI ranking: 13.6%,20%,10.6%)
[124] Chellakannu Rajkumar, Raja Nehru, Shen-Ming Chen, Haekyoung Kim, S Arumugam, Raman Sankar, 2019, “Electrosynthesis of carbon aerogel-modified AuNPs@quercetin via an environmentally benign method for hydrazine (HZ) and hydroxylamine (HA) detection”, NEW JOURNAL OF CHEMISTRY, 44, 586-595. (SCIE) (IF: 3.925; SCI ranking: 44.4%)
[125] Rajesh Kumar Ulaganathan, Raman Sankar, Chang‐Yu Lin, Raghavan Chinnambedu Murugesan, Kechao Tang, Fang‐Cheng Chou, 2019, “High‐Performance Flexible Broadband Photodetectors Based on 2D Hafnium Selenosulfide Nanosheets”, ADVANCED ELECTRONIC MATERIALS, 6, 1900794. (SCIE) (IF: 7.633; SCI ranking: 22.8%,32.7%,16.1%)
[126] CQ Xu, B Li, JJ Feng, WH Jiao, YK Li, SW Liu, YX Zhou, Raman Sankar, Nikolai D Zhigadlo, HB Wang, ZD Han, B Qian, W Ye, W Zhou, Toni Shiroka, Pabitra K Biswas, Xiaofeng Xu, ZX Shi, 2019, “Two-gap superconductivity and topological surface states in TaOsSi”, PHYSICAL REVIEW B, 13-134503. (SCIE) (IF: 3.908; SCI ranking: 47.1%,32.3%,33.3%)
[127] QR Zhang, B Zeng, YC Chiu, R Schönemann, S Memaran, W Zheng, D Rhodes, K-W Chen, T Besara, R Sankar, F Chou, GT McCandless, JY Chan, N Alidoust, S-Y Xu, I Belopolski, MZ Hasan, FF Balakirev, L Balicas, 2019, “Possible manifestations of the chiral anomaly and evidence for a magnetic field induced topological phase transition in the type-I Weyl semimetal TaAs”, PHYSICAL REVIEW B, 11-115138. (SCIE) (IF: 3.908; SCI ranking: 47.1%,32.3%,33.3%)
[128] Raman Sankar, I Panneer Muthuselvam, K Ramesh Babu, G Senthil Murugan, Karthik Rajagopal, Rakesh Kumar, Tsung-Chi Wu, Cheng-Yen Wen, Wei-Li Lee, Guang-Yu Guo, Fang-Cheng Chou, 2019, “Crystal Growth and Magnetic Properties of Topological Nodal-Line Semimetal GdSbTe with Antiferromagnetic Spin Ordering”, INORGANIC CHEMISTRY, 17-11730. (SCIE) (IF: 5.436; SCI ranking: 10.9%)
[129] Khasim Saheb Bayikadi, Raman Sankar, Chien Ting Wu, Chengliang Xia, Yue Chen, Li-Chyong Chen, Kuei-Hsien Chen and Fang-Cheng Chou, 2019, “Enhanced thermoelectric performance of GeTe through in situ microdomain and Ge-vacancy control”, JOURNAL OF MATERIALS CHEMISTRY A, 7, 15181-15189. (SCIE) (IF: 14.511; SCI ranking: 10.9%,7.6%,7.5%)
[130] Danil W Boukhvalov, Raju Edla, Anna Cupolillo, Vito Fabio, Raman Sankar, Yanglin Zhu, Zhiqiang Mao, Jin Hu, Piero Torelli, Gennaro Chiarello, Luca Ottaviano, Antonio Politano, 2019, “Surface Instability and Chemical Reactivity of ZrSiS and ZrSiSe Nodal‐Line Semimetals”, ADVANCED FUNCTIONAL MATERIALS, 29, 1900438. (SCIE) (IF: 19.924; SCI ranking: 5.6%,6.1%,4.9%,7.3%,5%,8.7%)
[131] Davide Iaia, Chang-Yan Wang, Yulia Maximenko, Daniel Walkup, R Sankar, Fang cheng Chou, Yuan-Ming Lu, Vidya Madhavan, 2019, “Topological nature of step-edge states on the surface of the topological crystalline insulatorPb0.7Sn0.3Se”, PHYSICAL REVIEW B, 99, 155116. (SCIE) (IF: 3.908; SCI ranking: 47.1%,32.3%,33.3%)
[132] S. Kalish, C. Chamon, M. El-Batanouny, L. H. Santos, R. Sankar, and F. C. Chou, 2019, “Contrasting the Surface Phonon Dispersion of Pb0.7Sn0.3Se in Its Topologically Trivial and Nontrivial Phases”, PHYSICAL REVIEW LETTERS, 122, 116101. (SCIE) (IF: 9.185; SCI ranking: 9.3%)
[133] Hung-Chang Hsu, Bo-Chao Huang, Shu-Cheng Chin, Cheng-Rong Hsing, Duc-Long Nguyen, Michael Schnedler, Raman Sankar, Rafal E Dunin-Borkowski, Ching-Ming Wei, Chun-Wei Chen, Philipp Ebert, Ya-Ping Chiu, 2019, “Photodriven Dipole Reordering: Key to Carrier Separation in Metalorganic Halide Perovskites”, ACS NANO, 13, 4, 4402-4409. (SCIE) (IF: 18.027; SCI ranking: 7.2%,7.3%,5.8%,10%)
[134] C. Q. Xu, B. Li, M. R. van Delft, W. H. Jiao, W. Zhou, B. Qian, Nikolai D. Zhigadlo, Dong Qian, R. Sankar, N. E. Hussey, and Xiaofeng Xu, 2019, “Extreme magnetoresistance and pressure-induced superconductivity in the topological semimetal candidate YBi”, PHYSICAL REVIEW B, 99, 024110. (SCIE) (IF: 3.908; SCI ranking: 47.1%,32.3%,33.3%)
[135] Yinming Shao, Zhiyuan Sun, Ying Wang, Chenchao Xu, Raman Sankar, Alexander J Breindel, Chao Cao, Michael M Fogler, Andrew J Millis, Fangcheng Chou, Zhiqiang Li, Thomas Timusk, M Brian Maple, DN Basov, 2019, “Optical signatures of Dirac nodal lines in NbAs2”, PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 4-1168. (SCIE) (IF: 12.779; SCI ranking: 12.2%)
[136] Peramaiyan G., Sankar Raman, Muthuselvam I. Panneer, Lee Wei-Li, 2018, “Anisotropic magnetotransport and extremely large magnetoresistance in NbAs2 single crystals”, Scientific Reports, 8(1), 6414. (SCIE) (IF: 4.997; SCI ranking: 25.7%)
[137] Gao Shang, Flicker Felix, Sankar Raman, Zhao He, Ren Zheng, Rachmilowitz Bryan, Balachandar Sidhika, Chou Fangcheng, Burch Kenneth S., Wang Ziqiang, van Wezel Jasper, Zeljkovic Ilija, 2018, “Atomic-scale strain manipulation of a charge density wave”, Proceedings of the National Academy of Sciences, 115(27), 6986-6990.
[138] Hosen M. Mofazzel, Dimitri Klauss, Nandy Ashis K., Aperis Alex, Sankar Raman, Dhakal Gyanendra, Maldonado Pablo, Kabir Firoza, Sims Christopher, Chou Fangcheng, Kaczorowski Dariusz, Durakiewicz Tomasz, Oppeneer Peter M., Neupane Madhab, 2018, “Distinct multiple fermionic states in a single topological metal”, Nature Communications, 9(1), (2018) 9:3002. (SCIE) (IF: 17.694; SCI ranking: 8.1%)
[139] Shu G. J., Liou S. C., Karna S. K., Sankar R., Hayashi M., Chou F. C., 2018, “Dynamic surface electronic reconstruction as symmetry-protected topological orders in topological insulator Bi2Se3”, Physical Review Materials, 2(4), 044201. (SCIE) (IF: 3.98; SCI ranking: 46.2%)
[140] Duvjir Ganbat, Choi Byoung Ki, Jang Iksu, Ulstrup Søren, Kang Soonmin, Thi Ly Trinh, Kim Sanghwa, Choi Young Hwan, Jozwiak Chris, Bostwick Aaron, Rotenberg Eli, Park Je-Geun, Sankar Raman, Kim Ki-Seok, Kim Jungdae, Chang Young Jun, 2018, “Emergence of a Metal–Insulator Transition and High-Temperature Charge-Density Waves in VSe2 at the Monolayer Limit”, Nano Letters, 18(9), 5432-5438. (SCIE) (IF: 12.262; SCI ranking: 11.1%,15.2%,9.2%,15.5%,8.1%,14.5%)
[141] Hakl M., Tchoumakov S., Crassee I., Akrap A., Piot B. A., Faugeras C., Martinez G., Nateprov A., Arushanov E., Teppe F., Sankar R., Lee Wei-li, Debray J., Caha O., Novák J., Goerbig M. O., Potemski M., Orlita M., 2018, “Energy scale of Dirac electrons in Cd3As2”, Physical Review B, 97(11), 115206. (SCIE) (IF: 3.908; SCI ranking: 47.1%,32.3%,33.3%)
[142] Li Yang, Wang Tianmeng, Wang Han, Li Zhipeng, Chen Yanwen, West Damien, Sankar Raman, Ulaganathan Rajesh K., Chou Fangcheng, Wetzel Christian, Xu Cheng-Yan, Zhang Shengbai, Shi Su-Fei, 2018, “Enhanced Light Emission from the Ridge of Two-Dimensional InSe Flakes”, Nano Letters, 18(8), 5078-5084. (SCIE) (IF: 12.262; SCI ranking: 11.1%,15.2%,9.2%,15.5%,8.1%,14.5%)
[143] B Li, CQ Xu, W Zhou, WH Jiao, R Sankar, FM Zhang, HH Hou, XF Jiang, B Qian, B Chen, AF Bangura and Xiaofeng Xu, 2018, “Evidence of s-wave superconductivity in the non-centrosymmetric La 7 Ir 3”, SCIENTIFIC REPORTS, 8, 651. (SCIE) (IF: 4.997; SCI ranking: 25.7%)
[144] IP Muthuselvam, R Sankar, GN Rao, SK Karna, FC Chou, 2018, “Ferromagnetic nature in low-dimensional S= 1 antiferromagnetic Li 2 Ni(WO 4 ) 2 nanoparticles”, JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS, 449, 83-87. (SCIE) (IF: 3.097; SCI ranking: 59.5%,50.7%)
[145] Huang Ce, Narayan Awadhesh, Zhang Enze, Liu Yanwen, Yan Xiao, Wang Jiaxiang, Zhang Cheng, Wang Weiyi, Zhou Tong, Yi Changjiang, Liu Shanshan, Ling Jiwei, Zhang Huiqin, Liu Ran, Sankar Raman, Chou Fangcheng, Wang Yihua, Shi Youguo, Law Kam Tuen, Sanvito Stefano, Zhou Peng, Han Zheng, Xiu Faxian, 2018, “Inducing Strong Superconductivity in WTe2 by a Proximity Effect”, ACS Nano, 12(7), 7185-7196. (SCIE) (IF: 18.027; SCI ranking: 7.2%,7.3%,5.8%,10%)
[146] Walkup Daniel, Assaf Badih A., Scipioni Kane L., Sankar R., Chou Fangcheng, Chang Guoqing, Lin Hsin, Zeljkovic Ilija, Madhavan Vidya, 2018, “Interplay of orbital effects and nanoscale strain in topological crystalline insulators”, Nature Communications, 9(1), 1550. (SCIE) (IF: 17.694; SCI ranking: 8.1%)
[147] Zhou W., Xu C. Q., Li B., Sankar R., Zhang F. M., Qian B., Cao C., Dai J. H., Lu Jianming, Jiang W. X., Qian Dong, Xu Xiaofeng, 2018, “Kondo behavior and metamagnetic phase transition in the heavy-fermion compound CeBi2”, Physical Review B, 97(19), 97, 195120. (SCIE) (IF: 3.908; SCI ranking: 47.1%,32.3%,33.3%)
[148] Raghavan Chinnambedu Murugesan, Chen Tzu-Pei, Li Shao-Sian, Chen Wei-Liang, Lo Chao-Yuan, Liao Yu-Ming, Haider Golam, Lin Cheng-Chieh, Chen Chia-Chun, Sankar Raman, Chang Yu-Ming, Chou Fang-Cheng, Chen Chun-Wei, 2018, “Low-Threshold Lasing from 2D Homologous Organic–Inorganic Hybrid Ruddlesden–Popper Perovskite Single Crystals”, Nano Letters, 18(5), 3221-3228. (SCIE) (IF: 12.262; SCI ranking: 11.1%,15.2%,9.2%,15.5%,8.1%,14.5%)
[149] Uykur E., Sankar R., Schmitz D., Kuntscher C. A., 2018, “Optical spectroscopy study on pressure-induced phase transitions in the three-dimensional Dirac semimetal Cd3As2”, Physical Review B, 97(19), 195134. (SCIE) (IF: 3.908; SCI ranking: 47.1%,32.3%,33.3%)
[150] Roth S., Lee H., Sterzi A., Zacchigna M., Politano A., Sankar R., Chou F. C., Di Santo G., Petaccia L., Yazyev O. V., Crepaldi A., 2018, “Reinvestigating the surface and bulk electronic properties of Cd3As2”, Physical Review B, 97(16), 97, 165439. (SCIE) (IF: 3.908; SCI ranking: 47.1%,32.3%,33.3%)
[151] Dhavala Suri, Christopher Linderalv, Bogdan Karpiak, Linnea Anderson, Sandeep Kumar Singh, Andre Dankert, FC Chou., Raman Sankar., Paul Erhart, Saroj P Dash, RS Patel, 2018, “Resistivity Anomaly in Weyl Semimetal candidate Molybdenum Telluride (MoTe 2 )”, APPLIED PHYSICS LETTERS, AR- 00763, xxxx-xxxx. (SCIE) (IF: 3.971; SCI ranking: 31.1%)
[152] Raman Sankar. G Peramaiyan, I Panneer Muthuselvam, Cheng-Yen Wen, Xiaofeng Xu, FC Chou,, 2018, “Superconductivity in a misfit layered (SnS) 1.15 (TaS 2 ) compound”, Chemistry of Materials, xxxx, xxxx-xxxx. (SCIE) (IF: 10.508; SCI ranking: 18.8%,13.9%)
[153] Xu Chunqiang, Li Bin, Jiao Wenhe, Zhou Wei, Qian Bin, Sankar Raman, Zhigadlo Nikolai D., Qi Yanpeng, Qian Dong, Chou Fang-Cheng, Xu Xiaofeng, 2018, “Topological Type-II Dirac Fermions Approaching the Fermi Level in a Transition Metal Dichalcogenide NiTe2”, Chemistry of Materials, 30(14), 4823-4830. (SCIE) (IF: 10.508; SCI ranking: 18.8%,13.9%)
[154] Premasiri Kasun, Radha Santosh Kumar, Sucharitakul Sukrit, Kumar U. Rajesh, Sankar Raman, Chou Fang-Cheng, Chen Yit-Tsong, Gao Xuan P. A., 2018, “Tuning Rashba Spin–Orbit Coupling in Gated Multilayer InSe”, Nano Letters, 18(7), 4403-4408. (SCIE) (IF: 12.262; SCI ranking: 11.1%,15.2%,9.2%,15.5%,8.1%,14.5%)
[155] Jiwei Ling, Yanwen Liu, Zhao Jin, Sha Huang, Weiyi Wang, Cheng Zhang, Xiang Yuan, Shanshan Liu, Enze Zhang, Ce Huang, Raman Sankar, Fang-Cheng Chou, Zhengcai Xia and Faxian Xiu, 2018, “Two-dimensional transport and strong spin–orbit interaction in SrMnSb2”, CHINESE PHYSICS B, 27, 017504. (SCIE) (IF: 1.652; SCI ranking: 66.3%)
[156] Yang Li, Tianmeng Wang, Meng Wu, Ting Cao, Yanwen Chen, Raman Sankar, Rajesh Kumar Ulaganathan, Fang-Cheng Chou, Christian Wetzel, Chengyan Xu, Steven G Louie, Sufei Shi, 2018, “Ultrasensitive tunability of the direct bandgap of two-dimensional InSe flakes via strain engineering”, 2D MATERIALS, 5, 021002. (SCIE) (IF: 6.861; SCI ranking: 25.7%)
[157] Xun Jia, Shuyuan Zhang, Raman Sankar, Fang-Cheng Chou, Weihua Wang, K Kempa, EW Plummer, Jiandi Zhang, Xuetao Zhu, and Jiandong Guo, 2017, “Anomalous Acoustic Plasmon Mode from Topologically Protected States”, PHYSICAL REVIEW LETTERS, 119, 136805. (SCIE) (IF: 9.185; SCI ranking: 9.3%)
[158] Y Wang, G Luo, J Liu, R Sankar, NL Wang, F Chou, L Fu and Z Li, 2017, “Observation of ultrahigh mobility surface states in a topological crystalline insulator by infrared spectroscopy”, Nature Communications, 8.
[159] Wenqing Dai, Anthony Richardella, Renzhong Du, Weiwei Zhao, Xin Liu, C.X. Liu, Song-Hsun Huang, Raman Sankar, Fangcheng Chou, Nitin Samarth, and Qi Li, 2017, “Proximity-effect- induced Superconducting Gap in Topological Surface States- A point contact Spectroscopy study of NbSe 2 /Bi2Se 3”, SCIENTIFIC REPORTS, 7, 7631. (SCIE) (IF: 4.997; SCI ranking: 25.7%)
[160] YR Chang, PH Ho, CY Wen, TP Chen, SS Li, JY Wang, MK Li, CA Tsai, Raman Sankar, Wei-Hua Wang, Po-Wen Chiu, Fang-Cheng Chou, and Chun-Wei Chen, 2017, “Surface oxidation doping to enhance photo generated carrier separation efficiency for ultrahigh gain indium selenide photodetector”, ACS PHOTONICS, 4, 2930-2936. (SCIE) (IF: 7.077; SCI ranking: 24.6%,35.5%,12.7%,18.6%,23.2%)
[161] Schmoldt A, Benthe HF, Haberland G, Mills GC, Alperin JB, Trimmer KB, Morton JG, Burton JF, Isaac O, Thiemer K, Mandels M, Bose KS, Sarma RH, 1975, “Delineation of the intimate details of the backbone conformation of pyridine nucleotide coenzymes in aqueous solution.”, Biochemical and biophysical research communications, 66(4), 1173-9. (SCIE) (IF: 3.322; SCI ranking: 66%,54.2%)
[162] Schmoldt A, Benthe HF, Haberland G, Holder AA, Wootton JC, Baron AJ, Chambers GK, Fincham JR, 1975, “The amino acid sequence of Neurospora NADP-specific glutamate dehydrogenase. Peptic and chymotryptic peptides and the complete sequence.”, The Biochemical journal, 149(3), 757-73. (SCIE) (IF: 3.766; SCI ranking: 58.9%)
[163] Schmoldt A, Benthe HF, Haberland G, Rozengurt E, Heppel LA, Smith RJ, Bryant RG, Clarke C, Sheppard PM, 1975, “The genetics of the mimetic butterfly Hypolimnas bolina (L.).”, Philosophical transactions of the Royal Society of London. Series B, Biological sciences, 272(917), 229-65.
[164] F Le Mardele, I Mohelsky, D Jana, A Pawbake, J Dzian, W-L Lee, K Raju, R Sankar, C Faugeras, M Potemski, ME Zhitomirsky, M Orl, Unpublished, “Tuning THz magnons in a mixed van-der-Waals antiferromagnet”, PHYSICAL REVIEW B.

學術會議(研討會)論文

[1] Ambika Subramanian, Vasanthan Thirunavukkarasu, Rajesh Kumar Ulaganathan, Raman Sankar, Wen Siang Lew, Chang-Yu Lin, 2024, “Photoconduction Properties in Germanium Sulfide Nanosheets on Rigid and Flexible Substrates”, paper presented at 2024 8th IEEE Electron Devices Technology & Manufacturing Conference (EDTM), Bangalore, India: Institute of Electrical and Electronics Engineers, 2024-03-03 ~ 2024-03-06.

其他論文

[1] Huang Yu-Ting, Chen Yi-Hsun, Ho Yi-Ju, Huang Shih-Wei, Chang Yih-Ren, Watanabe Kenji, Taniguchi Takashi, Chiu Hsiang-Chih, Liang Chi-Te, Sankar Raman, Chou Fang-Cheng, Chen Chun-Wei, Wang Wei-Hua, 2018, “High-Performance InSe Transistors with Ohmic Contact Enabled by Nonrectifying Barrier-Type Indium Electrodes”, ACS Applied Materials & Interfaces, 10(39), 33450-33456.

發現與突破

[1] 西元年：2024
研究人員(中)：雷曼
研究人員(英)：SANKAR, RAMAN, Bayikadi Khasim Saheb, Imam Safdar, Tee Wei-Shen, Kavirajan Sugumaran, Chang Chiao-Yu*, Sabbah Amr, Fu Fang-Yu, Liu Ting-Ran, Chiang Ching-Yu, Shukla Dinesh, Wu Chien-Ting, Chen Li-Chyong, Chou Mei-Yin, Chen Kuei-Hsien
研究成果名稱(中)：Sb/W共摻雜GeTe中的超低晶格熱導率驅動高熱電優值
研究成果名稱(英)：Ultra-low lattice thermal conductivity driven high thermoelectric figure of merit in Sb/W co-doped GeTe
簡要記述(中)：高熱電性能是一項主要與晶格動力學調控相關的材料挑戰。我們的研究顯示，GeTe基化合物中由微結構變形引起的晶格應變導致了聲子散射。特別是在Ge₀.₈₅Sb₀.₁W₀.₀₅Te中，異常的晶格收縮、鎢間隙原子、鎢納米沉澱物以及重元素質量共同作用，使其在825 K時實現了超低的晶格熱導率（約0.2 Wm⁻¹K⁻¹）。該化合物在825 K時達到了創紀錄的高熱電優值zT（約2.93）。這項系統性研究發表於《Journal of Materials Chemistry A》（J. Mater. Chem. A, 2024, 12, 30892-30905）。
此外，該組合物在825 K的操作溫度下，其單支腿的熱電效率（η）高達約17%，估算出的裝置優值ZT約為1.38。
簡要記述(英)：High thermoelectric performance is a material challenge associated mainly with the manipulation of lattice dynamics. We showed that the lattice-strain-induced phonon scattering resulted from microstructural distortions in GeTe-based compounds. The unusual lattice shrinkage, W interstitials, W nanoprecipitates, and heavy elemental mass, in Ge0.85Sb0.1W0.05Te culminate in an ultralow lattice thermal conductivity of ∼0.2 Wm−1K−1 at 825 K. It resulted record high zT of ∼2.93 at 825 K. The systematic study was published in Journal of Materials Chemistry A (J. Mater. Chem. A, 2024, 12, 30892-30905). Further, the thermoelectric efficiency (η) as high as ∼17% has been obtained for a single leg in this composition at an operating temperature of 825 K, with an estimated device ZT value of ∼1.38.

主要相關著作：

Bayikadi Khasim Saheb, Imam Safdar, Tee Wei-Shen, Kavirajan Sugumaran, Chang Chiao-Yu*, Sabbah Amr, Fu Fang-Yu, Liu Ting-Ran, Chiang Ching-Yu, Shukla Dinesh, Wu Chien-Ting, Chen Li-Chyong, Chou Mei-Yin, Chen Kuei-Hsien, Sankar Raman*, 2024, “Ultra-low lattice thermal conductivity driven high thermoelectric figure of merit in Sb/W co-doped GeTe”, Journal of Materials Chemistry A, 12(44), 30892-30905. (SCIE) (IF: 11.9; SCI ranking: 14.9%,9.1%,9.3%)

[2] 西元年：2024
研究人員(中)：雷曼
研究人員(英)：SANKAR, RAMAN, Frank Y. Gao, Xinyue Peng, Xinle Cheng, Emil Viñas Boström, Dong Seob Kim, Ravish K. Jain, Deepak Vishnu, Kalaivanan Raju, Shang-Fan Lee, Michael A. Sentef, Takashi Kurumaji, Xiaoqin Li, Peizhe Tang, Angel Rubio & Edoardo Baldini
研究成果名稱(中)：范德瓦耳斯多鐵性材料中的巨型手性磁電振盪
研究成果名稱(英)：Giant chiral magnetoelectric oscillations in a van der Waals multiferroic
簡要記述(中)：近期發現的螺旋型范德瓦耳斯多鐵性材料在超薄極限下展現了二維手性磁電耦合的巨大潛力。我們對一個剝離的范德瓦耳斯多鐵性材料的單一對映體域進行了動態磁電耦合的精密測量。該研究成果已發表於《Nature》期刊（Nature 632, 273–279）。這些發現強調了在二維極限下，交織有序能夠實現獨特功能的潛力，並為開發在太赫茲速度下運行的范德瓦耳斯磁電設備鋪平了道路。
簡要記述(英)：The recent discovery of helical van der Waals multiferroics down to the ultrathin limit raises prospects of large chiral magnetoelectric correlations in two dimensions. We performed a precision measurement of the dynamical magnetoelectric coupling for an enantiopure domain in an exfoliated van der Waals multiferroic. The research paper was published in Nature journal (Nature 632, 273–279). These findings highlight the potential for intertwined orders to enable unique functionalities in the two-dimensional limit and pave the way for the development of van der Waals magnetoelectric devices operating at terahertz speeds.

主要相關著作：

Frank Y Gao, Xinyue Peng, Xinle Cheng, Emil Viñas Boström, Dong Seob Kim, Ravish K Jain, Deepak Vishnu, Kalaivanan Raju, Raman Sankar, Shang-Fan Lee, Michael A Sentef, Takashi Kurumaji, Xiaoqin Li, Peizhe Tang, Angel Rubio*, Edoardo Baldini*, 2024, “Giant chiral magnetoelectric oscillations in a van der Waals multiferroic”, NATURE, 632, 273-279.

[3] 西元年：2024
研究人員(中)：雷曼
研究人員(英)：SANKAR, RAMAN, R. Kalaivanan, Balaji Venkatesan, B. Dundi Sri Chandana, Rajesh Kumar Ulaganathan, G. Senthil Murugan, K. Moovendaran, Joydev Khatua, Li-Hsin Su, W. Zhou, Xiaofeng Xu, Chia-Seng Chang, Tien-Ming Chuang, Yoshiyuki Iizuka, I. Panneer Muthuselvam*, Horng-Tay Jeng*, and Kwang-Yong Choi*
研究成果名稱(中)：GdAsSe單晶的結構、磁性和電子特性：實驗與理論研究
研究成果名稱(英)：Structural, magnetic, and electronic properties of a GdAsSe single crystal: Experimental and theoretical studies
簡要記述(中)：以稀土為基底的RB6X6化合物（B為過渡元素，X為Si、Ge、Sn）展現了多種新穎的量子態，例如大型異常霍爾效應、Chern拓撲磁性以及旋迴自旋結構。在這項研究中，我們成功生長出高品質的GdAsSe單晶，並系統性地研究了其磁化率 [X(T, H)]、磁化強度 [M(H)]、熱容 [CP(T, H)]、電阻率[p(T, H)]及電子自旋共振（ESR）隨溫度與磁場變化的特性。相關研究成果已發表於《Physical Review B》（Phys. Rev. B 109, 184420）。
這些實驗揭示了GdAsSe的磁性、熱力學及電子特性，為理解稀土基化合物中的新穎量子態提供了重要的實驗依據。
簡要記述(英)：Rare-earth-based RB6X6 compounds (B=transition elements; X=Si, Ge, Sn) exhibit a myriad of novel quantum states such as large anomalous Hall effects, Chern topological magnetism, and a cycloidal spin structure. In this regard, we successfully grown a high-quality single-crystal of GdAsSe and systematically studied its magnetic susceptibility [X(T, H)], magnetization [M(H)], heat capacity [CP(T, H)], electrical resistivity [p(T, H)], and electron spin resonance (ESR) measurements as a function of temperature and magnetic field. The research paper was published in Physical Review B (Phys. Rev. B 109, 184420).

主要相關著作：

R. Kalaivanan, Balaji Venkatesan, B. Dundi Sri Chandana, Rajesh Kumar Ulaganathan, G. Senthil Murugan, K. Moovendaran, Joydev Khatua, Li-Hsin Su, W. Zhou, Xiaofeng Xu, Chia-Seng Chang, Tien-Ming Chuang, Yoshiyuki Iizuka, I. Panneer Muthuselvam*, Horng-Tay Jeng*, Kwang-Yong Choi*, and Raman Sankar*, 2024, “Structural, magnetic, and electronic properties of a GdAsSe single crystal: Experimental and theoretical studies”, PHYSICAL REVIEW B, 109(18), 184420-1-184420-11.

[4] 西元年：2024
研究人員(中)：雷曼
研究人員(英)：SANKAR, RAMAN, Je-Ho Lee, Seungyeol Lee, Youngsu Choi, Lukas Gries, Rüdiger Klingeler,* Kalaivanan Raju, Rajesh Kumar Ulaganathan, Raman Sankar,* Maeng-Je Seong,* and Kwang-Yong Choi*
研究成果名稱(中)：錳摻雜NiPS₃中磁有序結構與自旋糾纏激子的光學探測
研究成果名稱(英)：Optical Probe of Magnetic Ordering Structure and Spin-Entangled Excitons in Mn-Substituted NiPS3
簡要記述(中)：在范德瓦耳斯磁體中，磁激子耦合與光學現象的交互作用，提供了直接探測磁性有序結構、通過磁場操控激子特性，以及探索電子與磁性狀態間量子糾纏的新途徑。特別是NiPS₃，由於其激子狀態與材料的自旋配置密切相關，能夠承載自旋糾纏激子而備受矚目。本研究實驗證明，自旋糾纏激子可用於偵測Ni₁₋ₓMnₓPS₃（x = 0–0.1）中的磁性易軸。相關成果發表於《Advanced Functional Materials》（Adv. Funct. Mater. 2024, 34, 2405153）。
這項研究不僅提供了光學方法來描繪磁性有序結構，還揭示了自旋-激子糾纏態中退相干過程的相關機制，對未來的磁性與光電應用具有重要意義。
簡要記述(英)：In van der Waals magnets, the interplay between magneto-excitonic coupling and optical phenomena opens avenues for directly probing magnetic ordering structures, manipulating excitonic properties through magnetic fields, and exploring quantum entanglement between electronic and magnetic states. Notably, NiPS3 stands out for its capacity to host spin-entangled excitons, where the excitonic states are intricately tied with the material's spin configuration. Herein, it is experimentally showcased that the spin-entangled excitons can be utilized for detecting the magnetic easy axis in Ni1-xMnxPS3 (x = 0–0.1). The research paper was published in journal of Advanced Functional Materials (Adv. Funct. Mater. 2024, 34, 2405153) and these findings not only provide optical means to map out magnetic ordering structures but also offer insights into decoherence processes in spin-exciton entangled states.

主要相關著作：

Je‐Ho Lee, Seungyeol Lee, Youngsu Choi, Lukas Gries, Rüdiger Klingeler*, Kalaivanan Raju, Rajesh Kumar Ulaganathan, Raman Sankar*, Maeng‐Je Seong*, Kwang‐Yong Choi*, 2024, “Optical Probe of Magnetic Ordering Structure and Spin-Entangled Excitons in Mn-Substituted NiPS3”, ADVANCED FUNCTIONAL MATERIALS, 34(39), 2405153-1-2405153-9.

[5] 西元年：2023
研究人員(中)：雷曼
研究人員(英)：SANKAR, RAMAN
研究成果名稱(中)：鍵合的交替S=1自旋鏈Sr2Ni(SeO3)3的晶體生長和磁性質
研究成果名稱(英)：Crystal growth and magnetic properties of the coupled alternating S=1 spin chain Sr2Ni(SeO3)3
簡要記述(中)：博士和I. Panneer Muthuselvam博士通過使用同步輻射X射線粉末衍射、磁化率χ(H, T)和熱容量CP(H, T)測量以及密度泛函理論（DFT）計算，研究了拟一維S = 1交替自旋鏈化合物Sr2Ni(SeO3)3的結構、磁性和熱力學性質。χ(H, T)和CP(H, T)的數據顯示在TN = 3.4(3) K處存在長程反鐵磁序，並在Tm ≈ 7.8 K處存在短程序。短程磁序與95%的自旋熵在TN以上的釋放，表明1D自旋相關性在∼8TN附近持續存在的重要性。理論DFT計算使用廣義梯度近似確定了主要的交換相互作用，表明鏈間相互作用負責觀察到的長程磁序。此外，根據χ(T, H)和CP(T, H)的數據確定了Sr2Ni(SeO3)3的溫度-場相圖。有趣的是，在沿著硬軸方向施加外部場的情況下，Tm的非單調相界被發現。我們的結果表明，Sr2Ni(SeO3)3的基態和磁性行為取決於單離子各向異性、鍵的交替和鏈間相互作用的相互作用
簡要記述(英)：Dr. Raman Sankar and Dr I. Panneer Muthuselvaminvestigate the structural, magnetic, and thermodynamic properties of a quasi-one-dimensional (1D) S = 1 alternating spin chain compound Sr2Ni(SeO3)3 are investigated by using synchrotron x-ray powder diffraction, magnetic susceptibility χ(H, T ), and heat capacity CP(H, T ) measurements together with density functional theory (DFT) calculations. The χ(H, T ) and CP(H, T ) data reveal long-range antiferromagnetic order at TN = 3.4(3) K and short-range order at Tm ≈ 7.8 K. The short-range magnetic order together with 95% of spin entropy release above TN signifies the importance of 1D spin correlations persisting to ∼8TN. Theoretical DFT calculations with generalized gradient approximation determine leading exchange interactions, suggesting that interchain interactions are responsible for the observed long-range magnetic ordering. In addition, the temperature-field phase diagram of Sr2Ni(SeO3)3 is determined based on the χ(T, H) and CP(T, H) data. Interestingly, a nonmonotonic phase boundary of Tm is found for an external field applied along a hard axis. Our results suggest that the ground state and magnetic behavior of Sr2Ni(SeO3 )3 rely on the interplay of single-ion anisotropy, bond alternation, and interchain interactions

[6] 西元年：2023
研究人員(中)：雷曼
研究人員(英)：SANKAR, RAMAN, Chih‐Ying Huang, Hung‐Min Lin, Chun‐Hao Chiang, Hsin‐An Chen, Ting‐Ran Liu, Deepak Vishnu S. K, Jau‐Wern Chiou, Huang‐Ming Tsai, Way‐Faung Pong, Chun‐Wei Chen
研究成果名稱(中)：調控二維金屬磷三硫化物晶體的自旋交換作用與自旋選擇電子轉移以提升氧演化反應效率
研究成果名稱(英)：Manipulating Spin Exchange Interactions and Spin-Selected Electron Transfers of 2D Metal Phosphorus Trisulfide Crystals for Efficient Oxygen Evolution Reaction
簡要記述(中)：通過Co摻雜控制自旋交換相互作用和自旋選擇電子轉移，大幅提升了2D CoxFe₁₋ₓPS₃（x=0–0.45）范德瓦耳斯（vdW）單晶的氧析出反應（OER）性能。原始的FePS₃表現出反鐵磁軌道有序，而摻雜Co後的FePS₃因摻雜引發的磁交換相互作用出現了原子間鐵磁性。通過超導量子干涉裝置磁力計、原位X射線吸收近邊譜以及密度泛函理論模擬，揭示了2D Co摻雜FePS₃晶體中自旋交換相互作用和自旋選擇電子轉移與優異OER性能之間的關聯。
該研究成果發表於《Advanced Functional Materials》（Adv. Funct. Mater. 2023, 33, 2305792）。研究結果表明，通過摻雜操控2D vdW晶體的自旋交換相互作用以提升自旋選擇電子轉移效率，是提升其OER催化性能的有效策略。
簡要記述(英)：A significant enhancement of OER performance is demonstrated by controlling the spin-exchange interaction and spin-selected electron transfer of 2D CoxFe1−xPS3 (x = 0–0.45) van der Waals (vdW) single crystals through Co doping. The pristine FePS3 exhibits antiferromagnetic orbital ordering, while the Co-doped FePS3 exhibits the emergence of interatomic ferromagnetism due to doping-mediated magnetic exchange interactions. The correlation of spin-exchange interactions and spin-selected electron transfers of 2D Co-doped FePS3 crystals with a superior OER performance is further revealed by superconducting quantum interference device magnetometer, in situ X-ray absorption near edge spectra and density functional theory simulations. The research paper was published in journal of Advanced Functional Materials (Adv. Funct. Mater. 2023, 33, 2305792) and the result suggests that manipulating the spin-exchange interactions of 2D vdW crystals to enhance the spin-selected electron transfer efficiencies through doping is an effective strategy to boost their OER catalytic performances.

主要相關著作：

Chih‐Ying Huang, Hung‐Min Lin, Chun‐Hao Chiang, Hsin‐An Chen, Ting‐Ran Liu, Deepak Vishnu S. K, Jau‐Wern Chiou, Raman Sankar, Huang‐Ming Tsai, Way‐Faung Pong, Chun‐Wei Chen, 2023, “Manipulating Spin Exchange Interactions and Spin‐Selected Electron Transfers of 2D Metal Phosphorus Trisulfide Crystals for Efficient Oxygen Evolution Reaction”, Advanced Functional Materials, 33, 43-2305792.

[7] 西元年：2023
研究人員(中)：雷曼
研究人員(英)：SANKAR, RAMAN, Ulaganathan Rajesh Kumar, Roy Pradip Kumar, Mhatre Swapnil Milind, Murugesan Raghavan Chinnambedu, Chen Wei‐Liang, Lai Man‐Hong, Subramanian Ambika, Lin Chang‐Yu, Chang Yu‐Ming, Canulescu Stela, Rozhin Alex, Liang Chi‐Te*
研究成果名稱(中)：基於長鏈有機二胺夾層的二維混合鈣鈦礦非線性光學單晶的高性能光檢測器及角度依賴的隨機雷射光
研究成果名稱(英)：High-Performance Photodetector and Angular-Dependent Random Lasing from Long-Chain Organic Diammonium Sandwiched 2D Hybrid Perovskite Non-Linear Optical Single Crystal
簡要記述(中)：三維有機-無機金屬鹵化物鈣鈦礦因其卓越的特性、溶液加工性和成本效益，被認為是光電應用的優秀材料。我們利用二價的N1-甲基丙烷-1,3-二胺鎵陽離子（N-MPDA）作為有機間隔物，製備了一種穩定的厘米級長度的二維混合鈣鈦礦單晶（N-MPDA）[PbBr₄]。該單晶表現出穩定的光電性能、低閾值的隨機激光以及多光子發光/多諧波生成，相關成果發表於《Advanced Functional Materials》（Adv. Funct. Mater. 2023, 33, 2214078）。
(N-MPDA)[PbBr₄]單晶憑藉其卓越的光電性能，為高性能設備提供可能，並作為構建未來穩定電子和光電應用的動態材料。
簡要記述(英)：3D organic-inorganic metal halide perovskites are excellent materials for optoelectronic applications due to their exceptional properties, solution processability, and cost-effectiveness. We prepared a stable centimeter-long 2D hybrid perovskite (N-MPDA)[PbBr4] single crystal using divalent N1-methylpropane-1,3-diammonium (N-MPDA) cation as an organic spacer and its stable optoelectronic performance, low threshold random lasing, and multi-photon luminescence/multi-harmonic generation were reported in the journal of Advanced Functional Materials (Adv. Funct. Mater. 2023, 33, 2214078). The outstanding optoelectronic merits of (N-MPDA)[PbBr4] single crystal will offer a high-performance device and act as a dynamic material to construct stable future electronics and optoelectronic-based applications.

主要相關著作：

Ulaganathan Rajesh Kumar, Roy Pradip Kumar, Mhatre Swapnil Milind, Murugesan Raghavan Chinnambedu, Chen Wei‐Liang, Lai Man‐Hong, Subramanian Ambika, Lin Chang‐Yu, Chang Yu‐Ming, Canulescu Stela, Rozhin Alex, Liang Chi‐Te*, Sankar Raman*, 2023, “High‐Performance Photodetector and Angular‐Dependent Random Lasing from Long‐Chain Organic Diammonium Sandwiched 2D Hybrid Perovskite Non‐Linear Optical Single Crystal”, Advanced Functional Materials, 33(17), 2214078. (SCIE) (IF: 19.924; SCI ranking: 5.6%,6.1%,4.9%,7.3%,5%,8.7%)

[8] 西元年：2023
研究人員(中)：雷曼
研究人員(英)：SANKAR, RAMAN, Roshan Jesus Mathew, Kai-Hsiang Cheng, Christy Roshini Paul Inbaraj, Raman Sankar, Xuan P.A. Gao,* and Yit-Tsong Chen*
研究成果名稱(中)：一種反雙極低溫光電晶體管
研究成果名稱(英)：An Anti-Ambipolar Cryo-Phototransistor
簡要記述(中)：新型反雙極電晶體 (AAT) 是閘極可調整流器，具有多值邏輯電路的顯著潛力。在這項工作中，研究了 AAT 在低溫條件下的光電應用，AAT 裝置由垂直堆疊的 p-SnS 和 n-MoSe2 組成奈米片形成II型交錯能帶排列。靜電可調諧 p-SnS/n-MoSe2 低溫光電電晶體具有獨特的抗雙極特性和低溫增強光電表現。低溫光電晶體管表現出尖銳且高度對稱的特性77 K 時的抗雙極性傳遞曲線，峰谷比為 103在 1 V 的低偏壓下工作。高冷卻增強電荷電荷低溫光電電晶體的遷移率賦予此 AAT 裝置非凡的性能光電檢測能力。在 77 K 時，p-SnS/n-MoSe2 低溫光電電晶體，在 250−900 nm 光譜範圍內保持廣泛的光響應，展示了其 2 × 104 A W−1 的高響應度和7.5 × 1013 Jones，激發波長為 532 nm。高效能低工作電壓 p-SnS/n-MoSe2 低維光電電晶體77−150 K 適合低溫光電應用環境。此外，這種異質結構的低溫特性可以進一步擴展以設計多值邏輯電路低溫條件。
簡要記述(英)：Novel anti-ambipolar transistors (AATs) are gate tunable rectifiers with amarked potential for multi-valued logic circuits. In this work, theoptoelectronic applications of AATs in cryogenic conditions are studied, ofwhich the AAT devices consist of vertically stacked p-SnS and n- MoSe2nanoflakes to form a type-II staggered band alignment. An electrostaticallytunable p-SnS/n-MoSe2 cryo-phototransistor is presented with uniqueanti-ambipolar characteristics and cryogenic-enhanced optoelectronicperformance. The cryo-phototransistor exhibits a sharp and highly symmetricanti-ambipolar transfer curve at 77 K with the peak-to-valley ratio of 103operating under a low bias voltage of 1 V. The high cooling-enhanced chargemobilities in the cryo-phototransistor grant this AAT device remarkablephotodetection capabilities. At 77 K, the p-SnS/n-MoSe2 cryo-phototransistor,holding a broad photoresponse in the spectral range of 250−900 nm,demonstrates its high responsivity of 2 × 104 A W−1 and detectivity of7.5 × 1013 Jones with the excitation at 532 nm. The high-performancep-SnS/n-MoSe2 low-dimensional phototransistor with low operating voltagesat 77−150 K is eligible for optoelectronic applications in cryogenicenvironments. Furthermore, the cryo-characteristics of this heterostructurecan be further extended to design the mul-tivalued logic circuits operated incryogenic conditions.

[9] 西元年：2023
研究人員(中)：雷曼
研究人員(英)：SANKAR, RAMAN
研究成果名稱(中)：操控二維金屬磷三硫化物晶體的自旋交換相互作用和自旋選擇的電子轉移，以實現高效的氧進化反應。
研究成果名稱(英)：Manipulating Spin Exchange Interactions and Spin-Selected Electron Transfers of 2D Metal Phosphorus Trisulphide Crystals for Efficient Oxygen Evolution Reaction
簡要記述(中)：博士及其小組與國立臺灣大學材料科學與工程學系的陳俊維教授合作，成功展示了通過摻雜來操控二維范德瓦爾斯晶體的自旋交換相互作用，以增強自旋選擇的電子轉移效率，這是提高其氧進化反應（OER）催化性能的有效策略。該研究的顯著結果已發表在Adv. Funct. Mater. 2023, 2305792。由於氧分子在基態下偏好三重自旋態配置，電催化劑上的自旋極化電子可能促進平行自旋對齊的氧原子的生成，從而增強氧進化反應動力學。在這項研究中，通過鈷摻雜控制二維CoxFe1−xPS3（x=0–0.45）范德瓦爾斯（vdW）單晶的自旋交換相互作用和自旋選擇的電子轉移，顯示了氧進化反應性能的顯著提高。原始的FePS3表現出反鐵磁軌道排序，而摻雜的FePS3由於摻雜介導的磁性交換作用而表現出原子間的鐵磁性。在摻雜的FePS3晶體中，Fe和Co離子之間的耦合允許形成與原始FePS3相比更有效的自旋選擇的電子轉移通道。通過超導量子干涉儀、原位X射線吸收近邊緣光譜和密度泛函理論模擬
簡要記述(英)：For the first time, Dr Raman Sankar and his group, in collaboration with Prof. Chun-Wei Chen (Department of Materials Science and Engineering, National Taiwan University) has successfully demonstrated manipulating the spin-exchange interactions of 2D vdW crystals to enhance the spin-selected electron transfer efficiencies through doping is an effective strategy to boost their OER catalytic performances. The prominent results were published in Adv. Funct. Mater.2023, 2305792.Because oxygen molecules in the ground state favor a triplet spin configuration, spin-polarized electrons at electrocatalysts may promote the generation of parallel spin-aligned oxygen atoms, enhancing oxygen evolution reaction (OER) kinetics. In this study, a significant enhancement of OER performance is demonstrated by controlling the spin-exchange interaction and spin-selected electron transfer of 2D CoxFe 1−xPS3(x=0–0.45) van der Waals (vdW) single crystals through Co-doping. The pristine FePS3 exhibits antiferromagnetic orbital ordering, while the Co-doped FePS3 exhibits the emergence of interatomic ferromagnetism due to doping-mediated magnetic exchange interactions. The coupling between Fe and Co ions in the Co-doped FePS3crystal allows the formation of efficient spin-selective electron transfer channels compared to the pristine FePS3. The correlation of spin-exchange interactions and spin-selected electron transfers of 2D Co-doped FePS3 crystals with a superior OER performance is further revealed by superconducting quantum interference device magnetometer, in situ X-ray absorption near edge spectra, and density functional theory simulations. The result suggests that manipulating the spin-exchange interactions of 2D vdW crystals to enhance the spin-selected electron transfer efficiencies through doping is an effective strategy to boost their OER catalytic performances

主要相關著作：

Ghosh Rapti, Papnai Bhartendu, Chen Yu‐Siang, Yadav Kanchan, Sankar Raman, Hsieh Ya‐Ping, Hofmann Mario, Chen Yang‐Fang, 2023, “Exciton Manipulation for Enhancing Photo‐electrochemical Hydrogen Evolution Reaction in Wrinkled 2D Heterostructures”, Advanced Materials, 0, 2210746. (SCIE) (IF: 32.086; SCI ranking: 2.8%,2.4%,2.3%,2.7%,3.1%,2.9%)

[10] 西元年：2023
研究人員(中)：雷曼
研究人員(英)：SANKAR, RAMAN, Rapti Ghosh, Bhartendu Papnai, Yu-Siang Chen, Kanchan Yadav, Raman Sankar, Ya-Ping Hsieh, Mario Hofmann,* and Yang-Fang Chen*
研究成果名稱(中)：操控激子以增強皺曲的二維異質結構中的光電化學制氫反應
研究成果名稱(英)：Exciton Manipulation for Enhancing Photoelectrochemical Hydrogen Evolution Reaction in Wrinkled 2D Heterostructures
簡要記述(中)：博士及其小組，與楊芳榮教授和馬里奧·霍夫曼教授（國立臺灣大學）合作，研究了二維材料結構的交界面在無金屬條件下作為產氫反應（HER）的替代材料。迄今為止，HER一直僅限於不同成分或能帶結構的異質結構。這裡展示了基於皺曲的二維異質結構的局部應變調制的潛力，有助於實現光電催化活性的交界面。通過在皺曲的WS2單層中形成高應變和低應變的區域，實現了由於壓電效應而在橫向方向上實現的其能帶結構和內部電場的局部修改。這種結構由於光束滯和激子傳導向WS2皺痕的頂點，產生了有效的電子-正電子對生成，並增強了激子分離。此外，皺曲的形成在2D層和基板之間引起了一個空氣間隙，減少了界面散射效應，從而提高了電荷載流子的遷移率。對應變依賴的光催化HER過程的詳細研究表明，Tafel斜率減少了一倍，交換電流密度增強了30倍。最後，通過量子點的官能化優化光吸收，實現了前所未有的光電催化性能，為未來可伸縮形成應變調制的WS2納米交界提供了途徑，用於綠色能源生成。
簡要記述(英)：Dr. Raman Sankar and his group, in collaboration with Prof. Yang-Fang Chen and Prof. Mario Hofmann, (National Taiwan, University) investigate 2D materials’ junctions have demonstrated capabilities as metal-free alterna-tives for the hydrogen evolution reaction (HER). To date, the HER has been limited to heterojunctions of different compositions or band structures. Here, the potential of local strain modulation based on wrinkled 2D heterostruc-tures is demonstrated, which helps to realize photoelectrocatalytically active junctions. By forming regions of high and low tensile strain in wrinkled WS2monolayers, local modification of their band structure and internal electric field due to piezoelectricity is realized in the lateral direction. This structure produces efficient electron–hole pair generation due to light trapping and exciton funneling toward the crest of the WS2 wrinkles and enhances exciton separation. Additionally, the formation of wrinkles induces an air gap in-between the 2D layer and substrate, which reduces the interfacial scattering effect and consequently improves the charge-carrier mobility. A detailed study of the strain-dependence of the photocatalytic HER process demonstrates a 2-fold decrease in the Tafel slope and a 30-fold enhancement in exchange current density. Finally, optimization of the light absorption through function-alization with quantum dots produces unprecedented photoelectrocatalytic performance and provides a route toward the scalable formation of strain-modulated WS2 nanojunctions for future green energy generation.
[11] 西元年：2023
研究人員(中)：雷曼
研究人員(英)：SANKAR, RAMAN
研究成果名稱(中)：高性能光檢測器和角度依賴的長鏈有機二銨夾層二維混合鈣鈦礦非線性光學單晶體隨機激光器
研究成果名稱(英)：High-Performance Photodetector and Angular-Dependent Random Lasing from Long-Chain Organic Diammonium Sandwiched 2D Hybrid Perovskite Non-Linear Optical Single Crystal
簡要記述(中)：博士及其小組，與台灣國立台灣大學物理學系的梁啟德博士以及丹麥技術大學電氣與光子工程學系的Stela Canulescu教授合作，通過使用雙價N1-甲基丙烷-1,3-二銨（N-MPDA）陽離子作為有機間隔層，研究了穩定的厘米長的二維混合鈣鈦礦（N-MPDA）[PbBr4]單晶。這個生長出來的單晶展現了穩定的光電性能、低閾值的隨機激光和多光子螢光/多次諧波生成。使用(N-MPDA)[PbBr4]單晶製作的光導電裝置展現出卓越的光響應（在405納米處約為124 AW−1），比單價有機間隔層輔助的二維鈣鈦礦（如（BA）2PbBr4和（PEA）2PbBr4）高出約4個數量級，並具有較大的特定檢測度（約為1012 Jones）。作為光學增益介質，(N-MPDA)[PbBr4]單晶呈現出低閾值的隨機激光（約為6.5 μJ cm−2），具有角度依賴的窄線寬（約為0.1納米）和高品質因子（Q約為2673）。基於這些結果，(N-MPDA)[PbBr4]單晶的優越光電特性將提供高性能的裝置，並作為構建穩定未來電子和光電子應用的動態材料。
簡要記述(英)：Dr. Raman Sankar and his group, in collaboration with Chi-Te Liang of Department of Physics, National Taiwan University (Taiwan) and Prof. Stela Canulescu at Department of Electrical and Photonics Engineering, Technical University of Denmark, investigated a stable centimeter-long 2D hybrid perovskite (N-MPDA)[PbBr4] single crystal using divalent N1-methylpropane-1,3-diammonium (N-MPDA) cation as an organic spacer. The as-grown single crystal exhibits stable optoelectronic performance, low threshold random lasing, and multi-photon luminescence/multi-harmonic generation. A photoconductive device fabricated using (N-MPDA)[PbBr4] single crystal exhibits an excellent photo responsivity (≈124 AW−1 at 405 nm) that is ≈4 orders of magnitudes higher than that of monovalent organic spacer-assisted 2D perovskites, such as (BA)2PbBr4 and (PEA)2PbBr4, and large specific detectivity (≈1012 Jones). As an optical gain media, the (N-MPDA)[PbBr4] single crystal exhibits a low threshold random lasing (≈6.5 μJ cm−2) with angular dependent narrow linewidth (≈0.1 nm) and high-quality factor (Q ≈ 2673). Based on these results, the outstanding optoelectronic merits of (N-MPDA)[PbBr4] single crystal will offer a high performance device and act as a dynamic material to construct stable future electronics and optoelectronic-based applications.
[12] 西元年：2022
研究人員(中)：雷曼
研究人員(英)：SANKAR, RAMAN, I Panneer Muthuselvam, R Madhumathy, K Saranya, K Moovendaran, Suheon Lee, Kwang-Yong Choi, Wei-tin Chen, Chin-Wei Wang, Peng-Jen Chen, M Ponmurugan, Min-nan Ou, Yang-Yuan Chen, Heung-Sik Kim, R Sankar
研究成果名稱(中)：鍵合的Jeff = 1/2交替鏈系統Sr2Co(SeO3)3的自旋單重基態
研究成果名稱(英)：Spin-singlet ground state of the coupled Jeff = 1/2 alternating chain system Sr2Co(SeO3)3
簡要記述(中)：博士及其小組，與中央研究院楊元樾教授、成均館大學的崔光勇教授（韓國）和班納拉斯印度大學的I.P.穆都塞爾瓦姆教授合作，通過磁化率χ(T)、磁特性熱Cm(T)、磁化和中子繞射測量以及第一性原理計算，研究了耦合的Jeff = 1/2交替鏈Sr2Co(SeO3)3化合物的結構、磁性、熱力學和電子性質。基於密度泛函理論的第一性原理計算表明，Sr2Co(SeO3)3形成一維鏈結構，具有鍵的交替和鏈間相互作用。磁化率χ(T)、磁特性熱Cm(T)和中子粉末繞射測量確認在100毫開爾文以下不發生長程磁有序。相反，χ(T)和Cm(T)中的最大值以及隨著T → 0 K時χ(T)和Cp(T)的指數下降指向自旋單重基態。基於J1-J2交替海森堡模型對χ(T)和Cm(T)的分析顯示，鍵的交替α = J2/J1 ≈ 0.7和自旋能隙Δ ≈ 3 K。最後，這項工作證明了Sr2Co(SeO3)3是一個基於自旋軌道纏繞Jeff = 1/2的耦合交替鏈系統。
簡要記述(英)：Dr. Raman Sankar and his group, in collaboration with Prof. Yang-Yuan Chen (IoP, Academia Sinica), Prof. Kwang-Yong Choi at Sungkyunkwan University (Republic of Korea) and Prof. I.P. Muthuselvam at Banaras Hindu University (India), investigated the structural, magnetic, thermodynamic, and electronic properties of a coupled Jeff = 1/2 alternating chain Sr2Co(SeO3)3 compound using magnetic susceptibility χ(T ), magnetic specific heat Cm(T ), magnetization, and neutron diffraction measurements along with first-principles calculations. The first-principles calculations based on the density functional theory suggest that Sr2Co(SeO3)3 forms a quasi-one-dimensional chain with bond alternation and interchain interactions. χ(T ), Cm(T ), and neutron powder diffraction measurements confirm that no long-range magnetic ordering occurs down to 100 mK. Instead, a maximum in χ(T ) and Cm(T ) and an exponential drop of χ(T ) and Cp(T ) as T → 0 K point to a spin-singlet ground state. The analysis of χ(T ) and Cm(T ) based on a J1-J2 alternating Heisenberg model shows the bond alternation α = J2/J1 ≈ 0.7 and a spin gap of Δ ≈ 3 K. Finally, this work demonstrates that Sr2Co(SeO3)3 is a coupled alternating chain system based on spin-orbit entangled Jeff = 1/2.
[13] 西元年：2022
研究人員(中)：雷曼
研究人員(英)：SANKAR, RAMAN, Hikaru Takeda, Jiancong Mai, Masatoshi Akazawa, Kyo Tamura, Jian Yan, Kalimuthu Moovendaran, Kalaivanan Raju, Raman Sankar, Kwang-Yong Choi, Minoru Yamashita
研究成果名稱(中)：Kitaev自旋液體候選物Na2Co2TeO6中的平面熱霍爾效應
研究成果名稱(英)：Planar thermal Hall effects in the Kitaev spin liquid candidate Na2Co2TeO6
簡要記述(中)：博士及其小組，與東京大學固態物理研究所的山下實教授（日本）和成均館大學的崔光勇教授（韓國）合作，在沿著 a- 和 a∗-軸方向施加磁場（B）的情況下，研究了基於鈷的蜂巢反鐵磁體Na2Co2TeO6中基塔耶夫自旋液體候選體的紐曼熱導率（κxx）和平面熱霍爾導率（κxy）。κxy/T的溫度依賴性顯示拓撲玻色激發的出現。此外，κxy對磁場的依賴性在反鐵磁相的臨界磁場處呈現符號反轉，表明了拓撲磁子的Chern數分佈的變化。值得注意的是，在AFM相的一階轉變磁場和飽和磁場之間的B ǀǀ a∗區間內觀察到有限的κxy，這在蜂巢格的a∗軸周圍的雙折疊旋轉對稱性的無序狀態中是被禁止的，表明存在一種打破雙折疊旋轉對稱性的磁有序狀態。這些結果表明，在飽和磁場以下的整個場範圍內，該化合物存在拓撲磁子。
簡要記述(英)：Dr. Raman Sankar and his group, in collaboration with Prof. Minoru Yamashita at the Institute for Solid State Physics, University of Tokyo (Japan) and Prof. Kwang-Yong Choi at Sungkyunkwan University (Republic of Korea), investigated the longitudinal thermal conductivity (κxx) and the planar thermal Hall conductivity (κxy) in the Kitaev spin liquid candidate of the cobalt-based honeycomb antiferromagnet Na2Co2TeO6 in a magnetic field (B) applied along the a- and a∗-axes. The temperature dependen
[14] 西元年：2022
研究人員(中)：雷曼
研究人員(英)：SANKAR, RAMAN, Kalimuthu Moovendaran, Raju Kalaivanan, I Panneer Muthuselvam, K Ramesh Babu, Suheon Lee, CH Lee, Khasim Saheb Bayikadi, Namasivayam Dhenadhayalan, Wei-Tin Chen, Chin-Wei Wang, Yen-Chung Lai, Yoshiyuki Iizuka, Kwang-Yong Choi, Vladimir B Nalbandyan, Raman Sankar
研究成果名稱(中)：非質心Sr0.94Mn0.86Te1.14O6單晶三角形磁體
研究成果名稱(英)：Triangular Magnet Emergent from Noncentrosymmetric Sr0.94Mn0.86Te1.14O6 Single Crystals
簡要記述(中)：Raman Sankar博士及其團隊與韓國的研究小組，成均館大學的Kwang-Yong Choi教授和南方聯邦大學（俄羅斯）的Vladimir B. Nalbandyan教授合作，報告了使用自通量方法成功生長Sr0.94Mn0.86Te1.14O6（SMTO）的高品質單晶。通過中子粉末衍射（NPD）、單晶X射線衍射（SCXRD）、熱化學等手段研究了SMTO的結構、電子和磁學性質
簡要記述(英)：Dr. Raman Sankar and his group, in collaboration with research groups in the Republic of Korea, Prof. Kwang-Yong Choi at Sungkyunkwan University and Prof. Vladimir B. Nalbandyan at Southern Federal University (Russia), report the successful growth of high-quality single crystals of Sr0.94Mn0.86Te1.14O6 (SMTO) using a self-flux method. The structural, electronic, and magnetic properties of SMTO are investigated by neutron powder diffraction (NPD), single-crystal X-ray diffraction (SCXRD), thermodynamic, and nuclear magnetic resonance techniques in conjunction with density functional theory calculations. The previously reported P6̅2m structure of SrMnTeO6 with cations in prismatic coordination has been revised using NPD and SCXRD. NPD unambiguously determined octahedral (trigonal antiprismatic) coordination for all cations with the chiral space group P312 (no. 149), which is further confirmed by SCXRD data. The magnetic susceptibility and specific heat data evidence a weak antiferromagnetic order at TN = 6.6 K. The estimated Curie−Weiss temperature θCW = −21 K indicates antiferromagnetic interaction between Mn-ions. Furthermore, both the magnetic entropy and the 125Te nuclear spin-lattice relaxation rate showcase that short range spin correlations persist well above the Néel temperature. Our work demonstrates that Sr0.94(2)Mn0.86(3)Te1.14(3)O6 single crystals realize a noncentrosymmetric triangular antiferromagnet.
[15] 西元年：2022
研究人員(中)：雷曼
研究人員(英)：SANKAR, RAMAN, Ganesan Senthil Murugan, Suheon Lee, C Wang, H Luetkens, Kwang-Yong Choi, Raman Sankar
研究成果名稱(中)：一維雙鏈自旋-1/2反鐵磁體KNaCuP2O7的自旋動力學
研究成果名稱(英)：Spin dynamics of the one-dimensional double chain spin-½ antiferromagnet KNaCuP2O7
簡要記述(中)：Dr. Raman Sankar團隊與韓國研究團隊合作（特別是成均館大學的Kwang-Yong Choi教授），研究了反鐵磁材料KNaCuP₂O₇的靜態與動態自旋磁化率。研究結合了μ子自旋鬆弛（μSR）技術與熱力學測量，探討了一維（1D）自旋S=½反鐵磁雙鏈KNaCuP₂O₇的自旋動力學。

透過零場與縱場μSR，研究測試了一維理論，探索自旋傳輸行為。靜態磁化率與比熱被均勻的一維自旋鏈模型很好地描述，其鏈內交互作用為J/kB ≈ 55 K，且鏈間交互作用較小。零場μSR揭示，自旋激發在高溫下表現為擴散性傳輸，隨溫度降至30 K以下逐漸轉變為彈道行為。此外，縱場μSR對外加磁場的變化不敏感，自旋動態磁化率的場獨立性與擴散或彈道行為均不一致。
簡要記述(英)：Dr. Raman Sankar and his group, in collaboration with research groups in the Republic of Korea, especially Prof. Kwang-Yong Choi at Sungkyunkwan University, investigated static and dynamic spin susceptibility of antiferromagnetic material KNaCuP2O7. They combined a muon spin relaxation (μSR) technique with thermodynamic measurements to explore the spin dynamics of one-dimensional (1D) S = ½ antiferromagnetic double chain KNaCuP2O7. They tested the 1D theory by probing spin transport using zero and longitudinal-field μSR. A uniform 1D spin chain model well describes static magnetic susceptibility and specific heat with the intrachain interaction J/kB ≈ 55 K and small interchain interactions. Spin excitations probed by zero-field μSR manifest that high-temperature diffusive spin transport turns into ballistic behavior with decreasing temperature below 30 K. In addition, they observe that longitudinal-field μSR varies hardly with an external magnetic field. The field-independent dynamical spin susceptibility disagrees with diffusive or ballistic behaviors.
[16] 西元年：2022
研究人員(中)：雷曼
研究人員(英)：SANKAR, RAMAN, Jan Wyzula, Xin Lu, David Santos-Cottin, Dibya Kanti Mukherjee, Ivan Mohelský, Florian Le Mardelé, Jiˇrí Novák, Mario Novak, Raman Sankar, Yuriy Krupko, Benjamin A. Piot, Wei-Li Lee, Ana Akrap, Marek Potemski, Mark O. Goerbig, and Milan Orlita*
研究成果名稱(中)：狄拉克節點線中的洛倫茲升壓驅動磁光半金屬
研究成果名稱(英)：Lorentz-Boost-Driven Magneto-Optics in a Dirac Nodal-Line Semimetal
簡要記述(中)：晶體固體的光學響應在很大程度上是由激發驅動的促進各能帶之間的電子。這允許一個人申請透過實驗確定能量的光學和磁光方法帶隙－對於我們理解任何事物都至關重要的基本屬性堅固－具有極高的精度。這裡表明，這種傳統的過去在許多材料上取得巨大成功的方法，並不研究具有色散節點線的拓樸狄拉克半金屬。在那裡，光學推導的帶隙取決於磁場的方向相對於晶軸。這種極不尋常的行為在由洛倫茲增強驅動的帶隙重整化項，其結果來自與相關的狄拉克哈密頓量的洛倫茲協變形式低能量時的節點線
簡要記述(英)：Optical response of crystalline solids is to a large extent driven by excitationsthat promote electrons among individual bands. This allows one to applyoptical and magneto-optical methods to determine experimentally the energyband gap —a fundamental property crucial to our understanding of anysolid—with a great precision. Here it is shown that such conventionalmethods, applied with great success to many materials in the past, do notwork in topological Dirac semimetals with a dispersive nodal line. There, theoptically deduced band gap depends on how the magnetic field is orientedwith respect to the crystal axes. Such highly unusual behavior is explained interms of band-gap renormalization driven by Lorentz boosts which resultsfrom the Lorentz-covariant form of the Dirac Hamiltonian relevant for thenodal line at low energies.
[17] 西元年：2022
研究人員(中)：雷曼
研究人員(英)：SANKAR, RAMAN, Rajesh Kumar Ulaganathan,* Raghavan Chinnambedu Murugesan,* Chang-Yu Lin, Ambika Subramanian, Wei-Liang Chen, Yu-Ming Chang, Alex Rozhin, and Raman Sankar*
研究成果名稱(中)：基於甲脒的穩定公分級二維鉛鹵化物鈣鈦礦單晶：用於長壽命光電應用
研究成果名稱(英)：Stable Formamidinium-Based Centimeter Long Two-Dimensional Lead Halide Perovskite Single-Crystal for Long-Live Optoelectronic Applications
簡要記述(中)：二維金屬鹵化物鈣鈦礦因其內在的多量子井結構和可溶液加工性，在成本效益高的光電應用中具有巨大潛力。然而，材料穩定性不足仍是實際應用中的主要挑戰。本研究展示了基於甲脒（FA）的公分級二維鈣鈦礦單晶（(BA)₂FAPb₂I₇），透過控制兩層鈣鈦礦厚度實現穩定的光電性能。

該大面積單晶展現出良好的結晶性、相純度和光譜均勻性。與基於甲胺（MA）的(BA)₂MAPb₂I₇相比，(BA)₂FAPb₂I₇單晶在大氣條件下具有優異的穩定性。利用剛性Si/SiO₂基板製備的光檢測器表現出高光響應度（Rλ ≈ 5 A W⁻¹）、快速響應時間（<20 ms）、特定探測率（D* ≈ 3.5 × 10¹¹ Jones），並在488 nm雷射照射下具有卓越的耐用性。Rλ和D*分別是基於(BA)₂MAPb₂I₇單晶的25倍與三個數量級。

此外，將該材料應用於柔性聚合物基板時，在彎曲與非彎曲狀態下均展現良好的光感應性能，顯示其在柔性與穩定光電應用中的潛力。
簡要記述(英)：Solution-processable 2D metal-halide perovskites are highly promising for cost-effective optoelectronic applications due to their intrinsic multiquantum well structure. However, the lack of stability is still a major obstacle in the use of this class of materials in practical devices. Here, the authors demonstrate the stable optoelectronic properties using formamidinium (FA)-based centimeter-long 2D perovskite (BA)2FAPb2I7 high-quality single-crystal controlled by the thickness of two perovskite layers. The large area single-crystal exhibits good crystallinity, phase purity, and spectral uniformity. Moreover, the (BA)2FAPb2I7 single-crystal shows excellent stability at open atmospheric conditions when compared to methylammonium (MA)-based (BA)2MAPb2I7 counterparts. The photodetectors fabricated using 2D perovskite single-crystal on the rigid Si/SiO2 substrate reveal high photoresponsivity (Rλ)(≈5 A W−1), the fast response time (<20 ms), specific detectivity (D*) (≈3.5 × 1011 Jones), and excellent durability under 488 nm laser illumination. The Rλ and D* values are obtained from the (BA)2FAPb2I7 single-crystal 25 times and three orders magnitudes, respectively, higher than the (BA)2MAPb2I7 single-crystal. Additionally, the perovskite material on flexible polymer substrate reveals good photo-sensing properties in both bending and nonbending states.
[18] 西元年：2022
研究人員(中)：雷曼
研究人員(英)：SANKAR, RAMAN, Cheng-Chieh Lin 1,2, Shing-Jong Huang3, Pei-Hao Wu4, Tzu-Pei Chen5, Chih-Ying Huang1,2, Ying-Chiao Wang5, Po-Tuan Chen6, Denitsa Radeva7, Ognyan Petrov7, Vladimir M. Gelev7, Raman Sankar 8, Chia-Chun Chen9, Chun-Wei Chen 1,5,10✉ & Tsyr-Yan Yu 1,2,4✉
研究成果名稱(中)：重定向動力學的直接研究二維有機-無機雜化中A位陽離子的分佈以固態 NMR 測定鈣鈦礦
研究成果名稱(英)：Direct investigation of the reorientational dynamics of A-site cations in 2D organic-inorganic hybrid perovskite by solid-state NMR
簡要記述(中)：用於研究 A 位陽離子的重新取向動力學的方法有限在二維有機-無機雜化鈣鈦礦（2D OIHP）中，它發揮關鍵作用決定其物理特性的作用。在這裡，我們描述了一種研究方法使用固態 NMR 和穩定同位素標記分析 A 位陽離子的動力學。 2D 2H NMR結合甲基-d3-銨陽離子 (d3-MA) 的 OIHP 揭示了多種分子的存在MA 的重定向運動模式。旋轉回波雙共振 (REDOR) NMR包含 15N 和 13C 標記的甲基銨陽離子 (13C,15N-MA) 的 2D OIHP反映了 C 和 N 核之間經歷不同的平均偶極耦合運動模式。我們的研究揭示了 A 位陽離子動力學與有機間隔物的結構剛性，因此提供了分子層次的洞察二維 OIHP 的設計
簡要記述(英)：Limited methods are available for investigating the reorientational dynamics of A-site cationsin two-dimensional organic–inorganic hybrid perovskites (2D OIHPs), which play a pivotalrole in determining their physical properties. Here, we describe an approach to study thedynamics of A-site cations using solid-state NMR and stable isotope labelling. 2H NMR of 2DOIHPs incorporating methyl-d3-ammonium cations (d3-MA) reveals the existence of multiplemodes of reorientational motions of MA. Rotational-echo double resonance (REDOR) NMRof 2D OIHPs incorporating 15N- and 13C-labeled methylammonium cations (13C,15N-MA)reflects the averaged dipolar coupling between the C and N nuclei undergoing differentmodes of motions. Our study reveals the interplay between the A-site cation dynamics andthe structural rigidity of the organic spacers, so providing a molecular-level insight into thedesign of 2D OIHPs.
[19] 西元年：2022
研究人員(中)：雷曼
研究人員(英)：SANKAR, RAMAN, Khasim Saheb Bayikadia,b,1 , Safdar Imama,c,1 , Mohammad Ubaidd , Anver Azizd , Kuei-Hsien Chenb , Raman Sankara,⁎
研究成果名稱(中)：異價取代的高度無序GeTe化合物的影響熱電性能
研究成果名稱(英)：Effect of aliovalent substituted highly disordered GeTe compound's thermoelectric performance
簡要記述(中)：碲化鍺（GeTe）作為一種無鉛高性能熱電材料，近年來已廣泛應用。針對中溫 (500–800 K) 應用進行了廣泛研究。載子濃度和與原始 GeTe 相比，空位控制的 GeTe 化合物的熱導率降低。我們探討並優化了 Ge0.9−xSb0.1PxTe (x = 0.01–0.05) 材料的最高熱電性能曼斯在高溫下。使用 Sb/P (+3) 控制和操縱 Ge (+2) 的本徵 Ge 空位將電荷對功率因數改善的貢獻增加到∼42 μWcm−1 K−2，同時最小化晶格熱貢獻~0.4 W/mK。這導致熱電性能的提高對於 Ge0.88Sb0.1P0.02Te 樣品，約 2.4 @ 773 K。含有大量原子無序的 Sb/P 離子增加了點缺陷引起的散射效應，而拉伸的晶界揭示了晶格熱貢獻減少。目前的工作證明了磷作為共摻雜劑可提高 GeTe 運作時的平均熱電性能 (ZTavg) 值溫度範圍。
簡要記述(英)：As a lead-free high-performance thermoelectric material, germanium telluride (GeTe) has recently beenextensively studied for mid-temperature (500–800 K) applications. The carrier concentration and thethermal conductivity are reduced for vacancy-controlled GeTe compounds compared with pristine GeTe.We explored and optimized the Ge0.9−xSb0.1PxTe (x = 0.01–0.05) material's highest thermoelectric perfor-mance at elevated temperatures. Intrinsic Ge vacancy control and manipulation of Ge (+2) with Sb/P (+3)increased the charge contribution to power factor improvement to ∼42 μWcm−1 K−2 while minimizing thelattice thermal contribution to ∼0.4 W/mK. This resulted in an increase in thermoelectric performance of∼2.4 @ 773 K for the Ge0.88Sb0.1P0.02Te sample. The inclusion of atomically disordered Sb/P ions considerablyincreases the scattering effects caused by the point defect, whereas stretched grain boundaries reveal thedecreased lattice thermal contribution. The current work demonstrates the effectiveness of phosphorus as aco-dopant in increasing the average thermoelectric performance (ZTavg) value over the GeTe operatingtemperature range.

[20] 西元年：2022
研究人員(中)：雷曼
研究人員(英)：SANKAR, RAMAN, Somrita Dutta, Deepak Vishnu S. K, Sudipta Som, Rajneesh Chaurasiya, Dinesh Kumar Patel, Kalimuthu Moovendaran, Cheng-Chieh Lin, Chun-Wei Chen,* and Raman Sankar*
研究成果名稱(中)：具有逆磁熱效應的分段高可逆熱致變色層狀鈣鈦礦[(CH₂)₂(NH₃)₂]CuCl₄晶體
研究成果名稱(英)：Segmented Highly Reversible Thermochromic Layered Perovskite [(CH2)2(NH3)2]CuCl4 Crystal Coupled with an Inverse Magnetocaloric Effect
簡要記述(中)：層狀無鉛混合鈣鈦礦在有機電子學應用中相比三維(3D)材料具有更高優勢，因其易於合成且對多種環境條件表現出穩定性。為探討該類材料的多功能特性，我們通過溶液法生長並利用單晶X射線衍射對[(CH₂)₂(NH₃)₂]CuCl₄（EDA-CuCl₄）晶體進行結構表徵。

該晶體熱穩定性優異，具備高可逆熱致變色溫度（約503 K）、隨溫度顯著變化的電導率，以及強烈的特殊磁性。通過粉末X射線衍射與紫外-可見吸收光譜監測並解釋晶體隨溫度的結構變化。晶體的吸收帶在多次加熱/冷卻循環後僅有微小變化，顯示其穩定性極佳。此外，該Cu基混合鈣鈦礦在反鐵磁耦合層中具有強鐵磁交互作用，Néel溫度約為34 K。

磁熱效應研究顯示，因反鐵磁轉變與強鐵磁交互作用導致磁熵變化，該晶體表現出逆磁熱效應，表明其適合作為低溫磁冷技術的環保材料候選者。整體結果顯示，這種二維（2D）鈣鈦礦具有在廣泛溫度範圍內用於未來電子應用的多功能潛力。
簡要記述(英)：The layered, lead-free hybrid perovskites are superior in organic electronics compared to their three-dimensional (3D) counterparts due to their facile synthesis and promising stability to various environmental conditions. To learn more about the multifunctional side of such materials, a layered perovskite (EDA)CuCl4 [EDA is (CH2)2(NH3)2] crystal was grown in solution and crystallographically characterized by single-crystal X-ray diffraction. The crystal is thermally very stable and exhibits a high reversible thermochromic working temperature (∼503 K), intense conductivity changes with temperature, and strong exotic magnetic properties. The structural changes of the crystal with temperature are monitored and explained by powder X-ray diffraction and UV–vis absorption. The absorption band of the crystal shows little variation after repeated heating/cooling cycles, indicating admirable stability. Moreover, the Cu hybrid consists of a strong ferromagnetic interaction in antiferromagnetically coupled layers with a Néel temperature of about 34 K. The magnetocaloric effect of the crystal was investigated and found to be inverse due to the magnetic entropy change associated with the antiferromagnetic transition and the strong ferromagnetic interaction, indicating the suitability of the perovskite hybrid as a candidate for an environmentally friendly low-temperature magnetic cooling technology. The overall results promise a potential multipurpose two-dimensional (2D) perovskite for future electronic applications in a wide temperature range.

主要相關著作：

Dutta Somrita, Vishnu S. K Deepak, Som Sudipta, Chaurasiya Rajneesh, Patel Dinesh Kumar, Moovendaran Kalimuthu, Lin Cheng-Chieh, Chen Chun-Wei, Sankar Raman*, 2022, “Segmented Highly Reversible Thermochromic Layered Perovskite [(CH2)2(NH3)2]CuCl4 Crystal Coupled with an Inverse Magnetocaloric Effect”, ACS Applied Electronic Materials, 4(1), 521-530. (SCIE) (IF: 4.494; SCI ranking: 27.7%,38.7%)

[21] 西元年：2022
研究人員(中)：雷曼
研究人員(英)：SANKAR, RAMAN, Anjaiah Sheelam, Sakthipriya Balu, Adil Muneeb, Khasim Saheb Bayikadi, Dhenadhayalan Namasivayam, Erakulan E. Siddharthan, Arif I. Inamdar, Ranjit Thapa, Ming-Hsi Chiang, Song-Jeng Isaac Huang, and Raman Sankar*
研究成果名稱(中)：透過高價態Fe與Co³⁺位點提升LaNi₁₋ₓFe₀.₅ₓCo₀.₅ₓO₃鈣鈦礦的氧氧化還原活性
研究成果名稱(英)：Improved Oxygen Redox Activity by High-Valent Fe and Co3+ Sites in the Perovskite LaNi1−xFe0.5xCo0.5xO3
簡要記述(中)：透過異價取代來調控鈣鈦礦氧化物的電子結構是一種有潛力的策略，可用於開發成本低且高效的能源轉換與儲存設備電催化劑。本研究使用簡單的溶膠-凝膠法及後續的熱解步驟，設計並合成LaNi₁₋ₓFe₀.₅ₓCo₀.₅ₓO₃（LNFCO-ₓ，x = 0.0、0.4、0.5、0.6）作為在1 M KOH中的氧氧化還原反應電催化劑。

其中，LNFCO-0.5表現出最低的過電位及最高的電荷轉移動力學。與原始的LaNiO₃相比，LNFCO-0.5的氧氧化還原活性過電位降低了90 mV。在氧還原反應（0.7 V vs RHE）與氧析出反應（1.60 V vs RHE）中，LNFCO-0.5的質量活性分別為LaNiO₃的2.5倍與2.13倍。其雙功能指數（在電流密度10 mA cm⁻²氧析出與−1 mA cm⁻²氧還原之間的電位差）為0.98。

Fe與Co取代Ni位點使得d帶中心靠近費米能級，增加了速率決定步驟中*OH中間體的結合強度。此外，表面富含Fe³⁺Δ、Co³⁺以及部分氧化的Ni³⁺態，有助於調整eg軌道填充度，從而提升氧氧化還原活性。
簡要記述(英)：Tuning the electronic structure of perovskite oxides via aliovalent substitution is a promising strategy to attain inexpensive and efficient electrocatalysts for energy conversion and storage devices. Herein, following the d-band center positions and using a simple sol–gel method followed by a pyrolysis step, LaNi1–xCo0.5xFe0.5xO3 (LNFCO-x; x = 0.0, 0.4, 0.5, and 0.6) electrocatalysts are designed and synthesized for oxygen redox reactions in 1 M KOH. Among them, LNFCO-0.5 has exhibited the lowest overpotential and the highest charge transfer kinetics in oxygen redox reactions. Overall, a 90 mV lower overpotential was observed in oxygen redox activity of LNFCO-0.5 compared to that of pristine LaNiO3. The mass activity of LNFCO-0.5 in the oxygen reduction reaction (at 0.7 V vs RHE) and oxygen evolution reaction (1.60 V vs RHE) was calculated to be 2.5 and 2.13 times higher than that of LaNiO3, respectively. The bifunctionality index (potential difference between the oxygen evolution at a current density of 10 mA cm–2 and the oxygen reduction at a current density of −1 mA cm–2) of LNFCO-0.5 was found to be 0.98. The substitution of Fe and Co for the Ni-site shifted the d-band center close to the Fermi level, which can increase the binding strength of the *OH intermediate in the rate-determining step. Also, the surface was enriched with Fe3+Δ, Co3+, and partially oxidized Ni3+ states, which is susceptible to tune the eg-orbital filling for superior oxygen redox activity.

主要相關著作：

Sheelam Anjaiah, Balu Sakthipriya, Muneeb Adil, Bayikadi Khasim Saheb, Namasivayam Dhenadhayalan, Siddharthan Erakulan E., Inamdar Arif I., Thapa Ranjit, Chiang Ming-Hsi, Isaac Huang Song-Jeng, Sankar Raman*, 2022, “Improved Oxygen Redox Activity by High-Valent Fe and Co3+ Sites in the Perovskite LaNi1–xFe0.5xCo0.5xO3”, ACS Applied Energy Materials, 5(1), 343-354. (SCIE) (IF: 6.959; SCI ranking: 27.3%,32.8%,24.9%)

[22] 西元年：2022
研究人員(中)：雷曼
研究人員(英)：SANKAR, RAMAN, Safdar Imam, Khasim Saheb Bayikadi, Mohammad Ubaid, V.K. Ranganayakulu, Sumangala Devi, Bhalchandra S. Pujari, Yang-Yuan Chen, Li-Chyong Chen, Kuei-Hsien Chen, Feng-Li Lin, Raman Sankar*
研究成果名稱(中)：透過Mo摻雜在GeTe基化合物中誘導高密度微晶棒實現協同性能提升
研究成果名稱(英)：Achieving synergistic performance through highly compacted microcrystalline rods induced in Mo doped GeTe based compounds
簡要記述(中)：在無鉛熱電材料中，鍺碲（GeTe）因其在中溫範圍內的高熱電性能（ZT）而受到廣泛研究。然而，其高p型載子濃度（~10²¹ cm³）限制了進一步提升ZT的可能性。為了改善GeTe的環保性與熱電性能，我們研究了Mo摻雜的作用，其顯著優化了載子濃度，並首次揭示了伴隨高密度微晶棒的獨特微結構改變，包括緻密的晶界、高密度的平面缺陷和點缺陷，這些共同作用促進了全頻聲子散射，降低了熱導率。

此外，通過在Ge位點進行Sb/Bi與Mo的共摻雜，進一步降低了載子濃度與熱導率，從而實現更高的ZT值。其中，Bi共摻雜的效果尤為顯著，在Ge₀.₈₉Mo₀.₀₁Bi₀.₁Te的樣品組成中，於673 K達到最高ZT值約2.3。

本研究展示了一個令人興奮的隱藏機制，即通過Mo摻雜形成高密度微晶棒來進行微結構調控，從而在GeTe系統中實現高效能。
簡要記述(英)：Among the lead-free thermoelectric material, germanium telluride (GeTe) has been extensively investigated due to its high thermoelectric performance (ZT) in mid-temperature; however, high p-type carrier density (~1021 cm3) hinder its suitability for higher ZT. To enhance the thermoelectric performance of the environmentally favorable GeTe, we explored the Mo doping significantly optimizes the carrier concentration along with uniquely unveiled microcrystalline rods accompanying compact grain boundaries, high-density planar defects, and point defects effectuating all-frequency phonon scattering yields to lower down the thermal conductivity. Furthermore, Sb/Bi co-doping with Mo at the Ge sites predominantly reduces the carrier concentration and thermal conductivity to attain a higher ZT. The codoping of Bi manifested a more prominent role in achieving the highest ZT of ~2.3 at 673 K for the sample composition with Ge0.89Mo0 $01Bi0.1Te. This study demonstrates an exciting hidden aspect of microstructural modification by forming highly dense microcrystalline rods through Mo doping to achieve high performance in the GeTe system.$

[23] 西元年：2021
研究人員(中)：雷曼
研究人員(英)：SANKAR, RAMAN, C. H. Lee , S. Lee, Y. S. Choi, Z. H. Jang, R. Kalaivanan, R. Sankar, * and K.-Y. Choi*
研究成果名稱(中)：Co基蜂巢晶格Na₂Co₂TeO₆中各向異性磁性相關性的多階段發展
研究成果名稱(英)：Multistage development of anisotropic magnetic correlations in the Co-based honeycomb lattice Na2Co2TeO6
簡要記述(中)：我們利用 ²³Na 核磁共振（NMR）與靜態磁化率 χ(T) 研究了 Co 基蜂巢晶格 Na₂Co₂TeO₆ 的磁性相關性隨溫度的演化行為。該化合物在 TN = 26 K 時展現三維（3D）長程磁性有序。當溫度降至 T* ≈ 110 K 時，簡單的順磁態發生交越，轉變為具相關性的順磁態，該狀態的核自旋晶格（1/T₁）與自旋自旋（1/T₂）弛豫率以及垂直於平面的 χ(T) 均顯示出冪律依賴性。

在磁場方向的依賴性研究中，1/T₁、1/T₂ 和 χ(T) 顯示了二維（2D）規範化經典特徵的各向異性自旋相關性。在磁性有序狀態下，我們觀察到四個連續的相變或交越，分別發生在 TN = 26 K、TN₁ = 16 K、TN₂ = 7 K 和 TN₃ = 3.5 K。這些多階段的相變和交越與2D和3D磁性有序的共存或有序自旋的重新定向有關。

研究結果表明，該化合物中存在多種挫折交互作用及其能階層次性，這些因素控制了複雜的磁性結構及各向異性磁性。
簡要記述(英)：We investigate the thermal evolution of magnetic correlations of the Co-based honeycomb lattice Na2Co2TeO6 with 23Na nuclear magnetic resonance and static magnetic susceptibility χ(T ). The studied compound shows three-dimensional (3D) long-range magnetic ordering at TN = 26 K. On cooling through T∗ ≈ 110 K, a simple paramagnetic state undergoes a crossover to a correlated paramagnetic state featuring a power-law dependence of the nuclear spin-lattice (1/T1) and spin-spin (1/T2) relaxation rates as well as of the out-of-plane χ(T ). The magnetic-field-direction dependence of 1/T1, 1/T2, and χ(T ) uncovers anisotropic spin-spin correlations of a two-dimensional (2D) renormalized classical character. In a magnetically ordered state, we are able to identify four successive transitions or crossovers occurring at TN = 26, TN1 = 16, TN2 = 7, and TN3 = 3.5 K. The multiple transitions and crossovers are associated with the coexistence of 2D and 3D magnetic orders or reorientation of the ordered spins. Our results suggest the presence of various types of frustrating interactions and their energy hierarchy that control complex magnetic structures and anisotropic magnetism.

主要相關著作：

Lee C. H., Lee S., Choi Y. S., Jang Z. H., Kalaivanan R., Sankar R., Choi K.-Y., 2021, “Multistage development of anisotropic magnetic correlations in the Co-based honeycomb lattice Na2Co2TeO6”, Physical Review B, 103(21), 214447. (SCIE) (IF: 3.908; SCI ranking: 47.1%,32.3%,33.3%)

[24] 西元年：2021
研究人員(中)：雷曼
研究人員(英)：SANKAR, RAMAN, Seungyeol Lee, Jaena Park, Youngsu Choi, Kalaivanan Raju, Wei-Tin Chen , Raman Sankar,* and Kwang-Yong Choi*
研究成果名稱(中)：Ni₁₋ₓFeₓPS₃磁性各向異性與相關性的化學調控
研究成果名稱(英)：Chemical tuning of magnetic anisotropy and correlations in Ni1−xFexPS3
簡要記述(中)：我們研究了范德瓦耳斯反鐵磁體Ni₁₋ₓFeₓPS₃的靜態磁化率與拉曼光譜隨溫度和成分的變化行為。NiPS₃與FePS₃分別展現XY型與Ising型磁性，使得透過化學方式調控磁性各向異性與自旋相關性成為可能。Ni₁₋ₓFeₓPS₃在x ≈ 0.1時由XY各向異性轉變為Ising各向異性。

儘管引入Fe後，XY各向異性迅速受到抑制，兩磁子散射顯示，在Fe含量高的範圍內，短程磁性相關性僅緩慢減弱。矛盾的是，隨著x的增加，兩磁子信號的能量重整化程度較低，儘管自旋數更大且經典磁性增強。靜態與動態磁性行為的差異表明，該合金范德瓦耳斯磁體中出現了一種新穎的自旋態。
簡要記述(英)：We report the temperature and composition dependence of static magnetic susceptibility and Raman spectroscopic measurements on van der Waals antiferromagnets Ni1−xFexPS3. The end members NiPS3 and FePS3 feature XY - and Ising-like magnetism, respectively, enabling chemical tuning of magnetic anisotropy and spin correlations. Ni1−xFexPS3 shows a turnover from the XY to Ising anisotropy through x ≈ 0.1. Although the XY anisotropy is rapidly suppressed on introducing Fe content, two-magnon scattering evidences the slow repression of short-range magnetic correlations deep inside the Fe-rich side. Counterintuitively, the two-magnon signal undergoes less renormalization of its energy with increasing x despite the larger spin number and enhanced classical magnetism. The disparate static and dynamic magnetic behaviors indicate the emergence of an exotic spin state in alloy van der Waals magnets.

主要相關著作：

Lee Seungyeol, Park Jaena, Choi Youngsu, Raju Kalaivanan, Chen Wei-Tin, Sankar Raman, Choi Kwang-Yong, 2021, “Chemical tuning of magnetic anisotropy and correlations in Ni1−xFexPS3”, Physical Review B, 104(17), 174412. (SCIE) (IF: 3.908; SCI ranking: 47.1%,32.3%,33.3%)

[25] 西元年：2020
研究人員(中)：雷曼
研究人員(英)：SANKAR, RAMAN, Khasim Saheb Bayikadi, Chien Ting Wu, Li-Chyong Chen, Kuei-Hsien Chen, Fang-Cheng Chou and Raman Sankar *
研究成果名稱(中)：利用應變域與域邊界協同最佳化Sb摻雜GeTe的熱電性能
研究成果名稱(英)：Synergistic optimization of thermoelectric performance of Sb doped GeTe with a strained domain and domain boundaries
簡要記述(中)：Dr. Raman Sankar的研究團隊首次系統性地報導了通過摻雜Sb對GeTe系統中Ge空缺的控制。伴隨著載子濃度的調控及Sb異價離子取代，實現了最佳摻雜水平（x = 0.10），在約800 K的高溫下達到2.35的熱電優值（ZT），顯著高於文獻中關於GeTe系統的單元素及多元素取代研究。
這項重要成果已於2020年2月13日發表在皇家化學學會的《Journal of Material Chemistry A》。
簡要記述(英)：For the first time Dr Raman Sankar group have reported the systematic vacancy control of Ge in GeTe system by doping Sb in to the system The concomitant carrier concentration ( and the aliovalent Sb ion substitution led to an optimal doping level of x= 0 10 to show ZT 2 35 near 800 K, which is significantly higher than those single and multi elementals substitution studies of GeTe system reported in literature The prominent results were published in Journal of Material Chemistry A, published by Royal Society of Chemistry on 13 Feb 2020.

主要相關著作：

Khasim Saheb Bayikadi, Chien Ting Wu, Li-Chyong Chen, Kuei-Hsien Chen, Fang-Cheng Chou, Raman Sankar, 2020, “Synergistic optimization of thermoelectric performance of Sb doped GeTe with a strained domain and domain boundaries”, JOURNAL OF MATERIALS CHEMISTRY A, 8, 5332-5341. (SCIE) (IF: 14.511; SCI ranking: 10.9%,7.6%,7.5%)

[26] 西元年：2019
研究人員(中)：雷曼
研究人員(英)：SANKAR, RAMAN, Khasim Saheb Bayikadi, Raman Sankar, Chien Ting Wu, Chengliang Xia, Yue Chen, Li-Chyong Chen, Kuei-Hsien Chen and Fang-Cheng Chou
研究成果名稱(中)：通過原位微區域和Ge空缺控制提升GeTe的熱電性能
研究成果名稱(英)：Enhanced thermoelectric performance of GeTe through in situ micro domain and Ge vacancy control
簡要記述(中)：Dr. Raman Sankar的研究團隊首次利用原位TEM分析證實了Ge空缺控制的證據，並首次成功在高達約500°C的高溫下穩定GeTe的菱面體相。這項重要成果已於2019年5月16日發表在皇家化學學會的《Journal of Material Chemistry – A》。
透過控制Ge空缺及對應的魚骨狀微域結構，GeTe的熱電性能提升超過60%，相較目前文獻記錄達到顯著增強。研究還報導了一種高度可重現的樣品製備方法，使純GeTe在菱面體結構下能穩定至約500°C，而不轉變為立方結構。
透過可逆的原位方法調控Ge空缺水平，GeTe粉末的熱電優值（ZT）在高溫（約500°C）下由約0.8提升至1.37，顯示出極高的可控性與再現性。
簡要記述(英)：For the first time Dr Raman Sankar group have reported the Ge vacancy control evidence with the help of In situ TEM analysis, Also for the first time have stabilized the GeTe phase in rhombohedral at higher temperature ~ 500 oC. The prominent results were published in Journal of Material Chemistry – A, published by Royal Society of Chemistry on May 16th 2019. Vacancy controlled GeTe with thick herring bone domains have enhanced the thermoelectric performance more than 60 % of the reported, up to date.A highly reproducible sample preparation method for pure GeTe in a rhombohedral structure without converting to the cubic structure up to ~ 500 oC is reported to show control of the Ge-vacancy level and the corresponding herringbone-structured micro domains. The thermoelectric figure-of-merit (ZT) for GeTe powder could be raised from ~ 0.8 to 1.37 at high temperature (HT) near ~ 500 oC by tuning the Ge-vacancy level through the applied reversible in situ route, which made it highly controllable and reproducible.

主要相關著作：

Khasim Saheb Bayikadi, Raman Sankar, Chien Ting Wu, Chengliang Xia, Yue Chen, Li-Chyong Chen, Kuei-Hsien Chen and Fang-Cheng Chou, 2019, “Enhanced thermoelectric performance of GeTe through in situ microdomain and Ge-vacancy control”, JOURNAL OF MATERIALS CHEMISTRY A, 7, 15181-15189. (SCIE) (IF: 14.511; SCI ranking: 10.9%,7.6%,7.5%)

雷曼 / 研究副技師

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