Preparation of Co–Pt alloy film magnets by electrodeposition

Abstract Co–Pt film magnets were prepared by electrodepositeion. The Co content in the films was varied from 24 to 57 at% by controlling the concentration of Co(SO 3 NH 2 ) 2 in a plating bath. Annealing of the as-deposited films transformed their crystal structure from the face-centered-cubic structure (fcc) to the ordered face-centered-tetragonal L1 0 structure (fct), and the coercivity increased to approximately 880 kA/m was successfully obtained.