Lanzhou Univ, Inst Phys Sci & Technol, Lanzhou 730000, Peoples R China
; Chinese Acad Sci, Inst High Energy Phys, Beijing 100049, Peoples R China
Phase depth profile in TiNi shape memory alloy films is studied by the combination of grazing-incidence X-ray diffraction and X-ray reflectivity measurement. The film is made from sputter-deposited Ni/Ti multilayers. At room temperature, both the phase depth profile and element depth profile are not uniform, and both have multilayer structure. There is a three-phase mixture region consisting of T3Ni4 precipitates, martensite and a little of austenite near the free surface. A uniform martensite phase is formed near the substrate. Diffusion and reaction take place between film and substrate. The simulation result of X-ray reflectivity shows that the results of film microstructure analysis are reasonable. It is the kinetic factors that mainly cause the ununiformity of phase depth profile in the film.