Structure, Magnetic Properties, and Phase Transformations in Electrodeposited Fe-Rich Fe–Pt Films

Fe rich Fe-Pt films with 56 at.%-75 at.% Fe are electrodeposited from an alkaline solution. A face-centered cubic (111) texture is clearly observed for as-deposited films with <;62 at.% Fe, while a body centered cubic (110) orientation is seen for higher Fe fraction. After annealing in forming gas for 1 h at or above 400 °C, a transformation to a face centered tetragonal (FCT) $L1_{0}$ phase was observed below 62 Fe at.%. With increasing Fe content, the annealed films show a texture change from (200) to (002); films with <;72% Fe show coercivity $\sim 7$ kOe while films with Fe above that value show small coercivity. Of particular interest are the 75 at.% films; these show a FCT structure after annealing at or above 450 °C, which differs from the $L1_{0}$ structure and is characterized by low anisotropy; in contrast, a relatively high out of plane coercivity (1-3 kOe) is observed in 75 at.% films in the as-deposited or annealed conditions up to 350 °C.