Patent ID: 7289298

Claim:
A perpendicular magnetic recording medium comprising: a substrate; an underlayer formed on the substrate, and containing at least one material selected from the group consisting of Ru, Pt, Pd, Cr, NiAl, MgO, Ti, CoCr, Ir, Ag, and Fe, and a perpendicular magnetic recording layer formed on the underlayer, having an easy axis of magnetization oriented perpendicularly to the substrate, and the perpendicular magnetic recording layer having magnetic crystal grains and a matrix surrounding the magnetic crystal grains, wherein the matrix contains at least one compound selected from the group consisting of AlAs, AlSb, Al 2 S 3 , Al 2 Se 3 , Al 2 Te 3 , CdS, CdSe, CdTe, GaAs, Ga 2 S 3 , In 2 S 3 , ZnS, ZnTe, and ZnSe; and wherein a ratio of a mass of the matrix in the perpendicular magnetic recording layer is 1 to 20 mol %.