Temperature of 4.3K Scanning tunneling microscope(STM)

Scanning tunneling microscope (STM) is one of the powerful tools in the research of surface and nanoscience. Not only the structure of the atom arrangement on the surface of material can be resolved but also the local electronic structure at atomic scale can be measured by using STM. Since STM was invented in 1981, both functions and techniques of STM are improved constantly. In particular, the current technique has been developed to render STM able to work in the environment of the low temperature and high magnetic field. Therefore developing the low temperature STM combining with the high magnetic field to explore new physics is the main goal of our group. This machine is the first home-built low temperature STM in Taiwan, which can be operated at the temperature of 4.3 K.

The components of the STM include:

Ultra-high vacuum chamber. 4.2 K liquid-helium cryostat. STM body. Sample preparation and evaporation systems. STM controller.	Low Temp STM

Sample preparation and evaporation systems	Ultra-high vacuum chamber

This STM has been established. It can be continuously operated for 120 hrs at 4.3 K after filling liquid helium of 12 liters. The attached figures are the images of surface electronic standing waves on Cu(111) and Au(111) surface, indicating our STM has a high stability.