Atomic-level study of a thickness-dependent phase change in gold thin films heated by an ultrafast laser.
An ultrafast laser-induced phase change in gold thin films with different thicknesses has been simulated by the method of coupling the two-temperature model and the molecular dynamics, including transient optical properties. Numerical results show that the decrease of film thickness leads to faster melting in the early nonequilibrium time and a larger melting depth. Moreover, earlier occurrence and a higher rate of resolidification are observed for the thicker film. Further analysis reveals that the mechanism for the thickness-dependent phase change in the films is the fast electron thermal conduction in the nonequilibrium state.
School of Aeronautics and Astronautics, Zhejiang University, Hangzhou, Zhejiang 310027, China. ganyong@zju.edu.cn
Yong
Y
Gan
Jixiang
J
Shi
Shan
S
Jiang
D003198:Computer Simulation; D006046:Gold / Q000737:chemistry; D006361:Heating; D006358:Hot Temperature; D007834:Lasers; D049329:Nanostructures / Q000737:chemistry*; D044367:Phase Transition; D013499:Surface Properties; D013997:Time Factors
D006046:Gold