MATERTRANS : Vol. 45 (2004) , No. 2 pp.350-352

Effect of Cobalt Addition on Shape Memory Properties of Ferromagnetic Ni-Mn-Ga Sputtered Films

Yoshiharu Katano¹⁾, Makoto Ohtsuka¹⁾, Minoru Matsumoto¹⁾, Kunihiro Koike²⁾ and Kimio Itagaki¹⁾

1) Institute of Multidisciplinary Research for Advanced Materials, Tohoku University
2) Department of Basic Technology, Faculty of Engineering, Yamagata University

(Received November 7, 2003)
(Accepted December 24, 2003)

Effect of adding cobalt on the shape memory properties of Ni-Mn-Ga sputtered films was investigated. It was found that the films containing cobalt less than 5.1 mol% has a single phase and those with more than 6.8 mol%Co has two phases. The Curie temperature increased and the saturation magnetization decreased with increasing cobalt content. These films exhibited one way shape memory effect. The shape recovery start temperature increased and the temperature range of shape change broadened with increasing cobalt content.

Keywords:

nickel-manganese-gallium, ferromagnetic shape memory alloy, Heusler type crystal structure, sputtered film, shape memory effect