Magnetic recording medium and magnetic recording and reproducing apparatus

Abstract

A perpendicular magnetic recording medium of the present invention comprises a non-magnetic substrate, and at least a backing layer, an under layer, an intermediate layer and a perpendicular magnetic recording layer, which are sequentially laminated on the non-magnetic substrate, wherein the backing layer is formed of a soft magnetic film having an amorphous structure, the under layer contains a NiW alloy containing any one or both of Co and Fe, the W content of the NiW alloy is within a range from 3 to 10 atom %, the total of the Co and Fe contents of the NiW alloy is 5 atom % or more and less than 40 atom %, the saturation magnetic flux density Bs of the NiW alloy is 280 emu/cm3 or more, the thickness of the under layer is within a range from 2 to 20 nm, and the intermediate layer contains Ru or a Ru alloy.

Dependencies are inferred from the claim text.