CO-FE-NI ALLOY FOR SOFT MAGNETIC FILM LAYER IN PERPENDICULAR MAGNETIC RECORDING MEDIUM, SPUTTERING TARGET MATERIAL, AND PERPENDICULAR MAGNETIC RECORDING MEDIUM

摘要

Disclosed is a soft magnetic Co-Fe-Ni alloy for a perpendicular magnetic recording medium, which has excellent saturation magnetic flux density, amorphousness, corrosion resistance and hardness. The Co-Fe-Ni alloy contains, in at%, 70-92% of Co + Fe + Ni (including 0% of Ni), 1-8% of Ta, and more than 7% but 20% or less of B. The composition of the Co-Fe-Ni alloy (expressed in at%) satisfies the following ratios: Co/(Co + Fe + Ni) of 0.1-0.9; Fe/(Co + Fe + Ni) of 0.1-0.65; Ni/(Co + Fe + Ni) of 0-0.35; and B/Ta of 1-8.