Thick-film permanent magnets by membrane electrodeposition

Thick films of nearly equiatomic Co-Pt produced by electrodeposition into nanoporous membranes exhibit an isotropic magnetic phase with square hysteresis loops ( M r ∕ M s = 0.95 ) and coercivity of up to 1.3 T. The initial magnetization curve is characteristic of pinning-type magnets. The coercivity can be controlled by the choice of annealing temperature or alloy composition, which depends on the chemical composition of the plating bath, properties which can be exploited to produce fine-pitch pole patterns.