スパッタリング法で作製したCu-Al-Ni薄膜の構造と形状記憶効果

抄録

The effects of the sputtering conditions such as substrate temperature, partial pressure of argon gas and sputtering power on the structures of sputter-deposited Cu-14 mass%Al-4 mass%Ni films were investigated by X-ray diffraction. The grain sizes of the films were very fine and less than about 1.0 μm in diameter. In the substrate temperature range from 373 to 573 K, the film structure was identified with a DO₃-type ordered bcc similar to that of the β₁ phase(Cu₃Al). The degree of ordering of the DO₃ structure decreased with decreasing substrate temperature and with decreasing partial pressure of argon gas. On the other hand, the crystal structure was independent of the sputtering power, remaining unchanged as to DO₃-type. The martensite transformation occurred between 293 and 123 K for the DO₃-type ordered films. The films sputter-deposited on an aluminum foil exhibited a good shape memory effect. Thus, these films may be useful as a shape memory composite material.