Deposition of Fe-Pd ferromagnetic shape memory alloy thin films by sputtering and their shape memory behavior

The purposes of this study are primarily to obtain basic knowledge of the fabrication of Fe-Pd ferromagnetic shape memory (SM) thin films and to investigate the effect of Pd content and thickness on the martensitic transformation behavior. Fe-Pd films were deposited onto fused quartz substrates by dual source sputtering. The crystal structures of as-sputtered films of Fe-28similar to30at%Pd and Fe-30similar to32at%Pd alloys were found to be bcc and fcc, respectively. It was observed that the crystal structure of Fe-28similar to30at%Pd films changed into a structure containing a fct phase after annealing at 900degreesC for 60 min followed by iced water quenching. The I'd content region where annealed films contain a fct structure tends to shift higher Pd with increasing film thickness. Annealed films containing fct phase underwent a thermoelastic fcc-to-fct martensitic transformation. The M-s temperature of films containing 28.5similar to30.0at% Pd was higher than RT, and it became lower with increasing Pd content. Fe-Pd films fabricated on thin Si substrates were found to show cyclic SM behavior under a constant magnetic bias force when temperature was changed repeatedly.