Insulator–metal transition and ultrafast crystallization of Ga40Sb60/Sn15Sb85 multiple interfacial nanocomposite films
The R–T curves of the phase change flms were measured using an in situ resistance–temperature test system to study the phase transition characteristics of the flms from amorphous to crystalline state. At the same time, the crystallization activation energy (Ea) of the flm was calculated with isothermal crystallization to evaluate its thermal stability. The refectance of the flm was measured by a near-infrared spectrophotometer (NIR, 7100 CRT, XINMAO, China), and the band gap was obtained by Kubelka–Munk’s law. The phase structure was analyzed using an X-ray difractometer (XRD, PANalytical, Netherlands) with Cu target, K ray, scanning angle range of 20°–60° in the scanning speed of 1° min?1. The change of flm thickness during crystallization was determined by an X-ray refectometer (XRR). The surface morphology of the flm was observed by atomic force microscopy (AFM, FM Nanoview 1000). The picosecond laser pumping probe system was employed to study the phase transition velocity by irradiating the flm with a mode-locked ytterbium-doped yttrium aluminum garnet laser at a wavelength of 532 nm for about 30 ps. The I–Vand R–V curves of the PCRAM device cells based on the GS/SS multiple interfacial flm were tested using a Tektronix AWG5012B arbitrary waveform generator and a Keithley 2602 A parameter analyzer.