NiTi合金薄膜厚度对相变温度影响的X射线光电子能谱分析

采用X射线衍射和X射线光电子能谱实验手段对不同厚度的NiTi薄膜相变温度的变化进行了分析.结果表明在相同衬底温度和退火条件下，3?μm厚度的薄膜晶化温度高于18?μm厚度的薄膜.衬底温度越高，薄膜越易晶化，退火后薄膜奥氏体相转变温度As越低.薄膜的表面有TiO₂氧化层形成，氧化层阻止了Ni原子渗出；膜与基片的界面存在Ti₂O₃和NiO.由于表面和界面氧化层的存在，不同厚度的薄膜内层的厚度也不同，因而薄膜越薄，Ni原子的含量就越高.Ni原子的含量的不同会影响薄膜的相变温度. 关键词： NiTi合金薄膜 X射线衍射 相变 X射线光电子能谱

X-ray photoelectron spectroscopy analysis of the effect of thickness on the transformation temperature of NiTi alloy thin films

The effect of thickness on transformation temperature of the NiTi thin films has been studied by X-ray diffraction and X-ray photoelectron spectroscopy. Results show that the crystallization temperature for 3?μm-thick film is higher than that for 18?μm thick film at the same growth temperature and post annealing. With the substrate temperature increasing, the start temperature （A_s） of austenite phase is lowered after annealing at 763 K for 1?h. There is an oxide layer （TiO₂） on the film surface, which prevents the Ni atom from coming onto the surface. There is an oxide layer of a mixture Ti₂O₃ with NiO on the film /substrate interface. The oxide layers affect the transformation temperature by changing the Ni atomic content in the interior of the film.
Keywords： NiTi alloy film X-ray diffraction phase transformation X-ray photoelectron spectroscopy