Effect of Phosphor Incorporation on Magnetic Properties of Electrodeposited CoPtW Thin Films

The electrochemical behaviors of CoPtW(P) electrodeposition have been analyzed by means of cyclic voltammetry. Effect of hypophosphite concentration in the electrolyte on the alloy composition, crystalline structure and magnetic properties has been investigated. It is turned out that the intensity of [00.1] P.O in the XRD pattern of CoPtW(P) has been strengthened when the concentration of hypophosphite increased from 0 to 0.1 M. Parallel and perpendicular coercivity of electrodeposited CoPtW(P) reached a maximum when the hypophosphite concentration was 0.06 M, but the perpendicular magnetic anisotropy increased gradually with the increase of hypophosphite concentration. Moreover, saturation magnetization of the electrodeposited CoPtW(P) with more P content decreased when the films were exposed to the air. This can be explained by the fact that the hydrogen evolution would be favored thanks to an increase of hypophosphite concentration, which led to the acceleration of corruption speed.