Patent ID: 7875371
Filing Date: 2011-01-25
Classification: G11B

Abstract:
1. A perpendicular magnetic recording medium including a perpendicular recording layer formed over a substrate with a soft magnetic underlayer therebetween, wherein said perpendicular magnetic recording medium further includes an amorphous layer or nano-crystalline layer formed directly above said substrate and directly below said soft magnetic underlayer; wherein said soft magnetic underlayer includes first and second amorphous soft magnetic layers, and a nonmagnetic layer formed between said first and second amorphous soft magnetic layers; and wherein said first and second amorphous soft magnetic layers are given uniaxial magnetic anisotropy in a radial direction of said substrate respectively and are coupled with each other antiferromagnetically; wherein said amorphous layer or nano-crystalline layer comprises a NiTaZr layer, wherein said amorphous layer or nano-crystalline layer includes an alloy that contains at least two or more types Al, Ti, Cr, Co, Hf, Si, and B metal elements.