The dynamic behavior of chemical reaction and epitaxial growth on surface is a crucial topic, and has attracted extensively attention in the category of surface science. Scanning tunneling microscope (STM) enables to directly observe the motion of single atom or molecular. The dynamics of surface species provides much information in atomic resolution, which markedly promotes the understanding of fundamental science.
It is well known that temperature is a significant factor in most physical phenomenon and chemical reaction. Diffusion of atoms, chemical reactions, and phase transitions are strongly affected by working temperature. STM in well control of temperature can provide lots of key evidences. The novel variable-temperature STM in our lab can monitor a specific area with a wide temperature range (50K~450K). It is significant to explore new physical phenomenon and understand fundamental mechanism of surface science. Currently, the on-going study in our lab is about mechanism of the epitaxial growth on semiconductor surfaces, focusing on details in early stage of the growth and phase transition of surface structures with temperature.