Crystallographic analysis of TiNi shape memory alloy thin film for microactuator

Basic research for the micro actuator using TiNi shape-memory alloy (SMA) is conducted from the crystallographic point of view. SMA (TiNi) thin film is fabricated by sputtering deposition. The influence of substrate temperature on crystal structure is verified by measuring resistivity-temperature characteristics and X-ray diffraction. Sputtered TiNi thin film under a low-temperature substrate condition showed amorphous structure. However, thin film sputtered at a high-temperature condition had a crystal lattice, and showed similar phase transformation characteristics as regular bulk TiNi. The results of applying electric current into amorphous TiNi film show that though annealing can encourage crystallization, it is not sufficient.<
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