Osamu Inagoya

MAGNETIC PROPERTIES OF FE-CU AND FE-P ELECTRODEPOSITED ALUMITE FILMS

Cu and P were examined as additives to decrease the perpendicular coercivity of Fe-electrodeposited alumite film. Addition of Cu and P to the Fe particles decreased the coercivity to less than 1000 Oe, and P was a more effective additive than Cu in decreasing the coercivity. In the Fe-Cu system, Cu atoms are considered to be dispersed uniformly in the Fe matrix because no drastic changes in the morphological, crystallographical and magnetic properties were observed. In the Fe-P system, P is considered to be precipitated between Fe microcrystallites because the crystallographic continuity of the Fe particles was deteriorated, and distinct microstructure was observed in the Fe particles when P was added. Drastic decrease in the coercivity of Fe-electrodeposited alumite film is considered to be mainly due to the discontinuity of the Fe particles in a system containing P.

CO-P ELECTRODEPOSITED ALUMITE FILMS WITH IN-PLANE MAGNETIZATION

The magnetic properties and corrosion resistance of a magnetic alumite film, in which micropores are filled with Co, are investigated. It is found that in-plane magnetizatlon film is obtained by adding a small amount of P to the Co. For example, the effective anisotropy energy of the film changes from +0.44×105 erg/cm3 to -1.32×105 erg/cm3 by the addition of 8 at.% P. The in-plane coercivity of the film can be controlled between 340 Oe and 1350 Oe by the P content. The corrosion resistance of the film filled with Co94P6 under the atmosphere of 40°C, 90% R. H. with 10 ppm SO2 gas is tested. The corrosion resistance of the film under this condition is superior to that of sputtered Co-Ni thin film media with a carbon protective layer. Magnetic alumite film filled with Co-P alloy is considered to be a candidate for longitudinal magnetic recording media.