SOFT MAGNETIC BACKING LAYER FILM FOR MAGNETIC RECORDING MEDIUM, SPUTTERING TARGET MATERIAL FOR FORMING SOFT MAGNETIC BACKING LAYER FILM FOR MAGNETIC RECORDING MEDIUM, AND METHOD FOR PRODUCING SOFT MAGNETIC BACKING LAYER FILM FOR MAGNETIC RECORDING MEDIUM

摘要

PROBLEM TO BE SOLVED: To provide a soft magnetic backing layer film for a magnetic recording medium, the film having an amorphous structure that can achieve saturation magnetic flux density and magnetic permeability both in high levels.;SOLUTION: The soft magnetic backing layer film for a magnetic recording medium comprises a Co-Fe alloy, wherein the composition ratio of Co and Fe represented by atomic% in the soft magnetic backing layer film is in the range from 88:12 to 92:8, and the film contains as additive elements, both of 3.0 atomic% or more of Zr and 2.0 atomic% or more of at least one kind, two kinds or more selected from a group consisting of B, Y, Nb Hf and Ta, with the total content of the additive elements ranging from 5.0 to 9.0 atomic%. A sputtering target material for forming the soft magnetic backing layer film for a magnetic recording medium is provided, having the same composition as above described. A method for manufacturing the soft magnetic backing layer film for a magnetic recording medium is also provided, in which the film is formed by a sputtering method using the above sputtering target.;COPYRIGHT: (C)2012,JPO&INPIT