Phase Change Behavior of Sn20Sb80/Si Nano-Composite Multilayer Thin Films
The crystallization temperature of the thin films could be obtainedby measuring the change of the resistance of the sample during theheating process through the in-situ resistance-temperature (R-T) testsystem. By studying the isothermal crystallization process at differenttemperatures, the crystal activation energy (Ec) and thermal stabilitycould be evaluated.10 In order to prevent the oxidation and volatilization of the film during heating, high purity Ar gas was led into thetest chamber for protection. The transmittance spectrum of the filmwas measured in the wavelength range from 900 to 2500 nm by usinga UV-visible-NIR spectrophotometer, and the optical bandgap wasobtained by using the Tauc formula. X-ray powder polycrystallinediffractometer (XRD) using Cu Kα radiation in the 2θ range from 20?to 60? with a scanning step of 0.01? was used to characterize the crystalline phase structure before and after the crystallization. The surfacemorphology of the film was observed by atomic force microscope(AFM, FM-Nanoview 1000). The phase change rate of the compositefilm was evaluated by the laser picosecond pump-probe test system,in which the duration and wavelength of the light irradiated on thefilm were 30 ps and 532 nm, respectively.
Xuan Guo, Yifeng Hu, Qingqian Chou,Tianshu Lai,Rui Zhang and Xiaoqin Zhu