MATERTRANS : Vol. 44 (2003) , No. 12 pp.2513-2519

Shape Memory Behavior of Ni-Mn-Ga Sputtered Films under a Magnetic Field

Makoto Ohtsuka¹⁾, Masaki Sanada¹⁾, Minoru Matsumoto¹⁾, Toshiyuki Takagi²⁾ and Kimio Itagaki¹⁾

1) Institute of Multidisciplinary Research for Advanced Materials, Tohoku University
2) Institute of Fluid Science, Tohoku University

(Received June 20, 2003)
(Accepted October 7, 2003)

The shape memory behavior under the magnetic field up to 5 T was observed in Ni-Mn-Ga sputtered films. The sputtered films were heat-treated at 1073 K for 36 ks for homogenization and aged at 673 K for 14.4 and 56.7 ks in a constraint condition. The martensitic transformation temperatures and Curie temperature of the obtained films were higher than room temperature. The martensitic transformation temperatures increased under a magnetic field. Furthermore, a shape memory effect was observed by increasing and decreasing of the magnetic field.

Keywords:

nickel-manganese-gallium, ferromagnetic shape memory alloy, sputter deposition, constraint-aging, shape memory effect, magnetic field