Nickel titanium films were fabricated by RF magnetron sputtering method with dual targets, NiTi and titanium. The titanium content of NiTi films was controlled by changing the input power into titanium target. The fabricated films were solution-treated at 900°C for 30 minutes and aging-treated at 400°C for 6 hours. The results are obtained as follows.
(1) It was possible to controll the titanium content of NiTi film by changing the input power into titanium target.
(2) Two types of films were obtained. One was nickel rich film that had the mixed structure of NiTi, Ti2Ni and Ni3Ti, and the other was titanium rich film that had the mixed structure of NiTi and Ti2Ni.
(3) NiTi films were transformed into martensite phase _??_ rhombohedral phase _??_ austenite phase. These transformation temperatures were determined by a differential scanning calorimeter. The transformation temperature of nickel rich layer was lower than that of titanium rich film. The temperature hysteresis between rhombohedral and martensite phases was small.
(4) The shape memory characteristics were observed at the transformation between austenite and rhombohedral phases. It was expected to use NiTi film for microactuators and microsensors.
