Patent ID: 8703307

Claim:
A perpendicular magnetic recording medium comprising: a soft magnetic underlayer formed above a substrate; a lower seed layer formed above the soft magnetic underlayer; at least one upper seed layer formed above the lower seed layer; and a perpendicular recording layer formed above the at least one upper seed layer; wherein the at least one upper seed layer comprises Ni or a Ni based alloy including N, wherein the lower seed layer includes Ni and at least one element selected from a group consisting of: W and Cr, wherein the at least one upper seed layer comprises a Ni alloy including N and at least one element selected from a group consisting of: V, Cr, Nb, Mo, Ta, and W, wherein the at least one upper seed layer includes N in a concentration range of about 0.2 at % to about 6.5 at % and Cr in a concentration range of about 1 at % to about 20 at %, wherein an average size of fine grains in the lower seed layer is greater than an average size of fine grains in the at least one upper seed layer, and wherein a perpendicular orientation of grains of the at least one upper seed layer is in the same direction as a perpendicular orientation of grains of the lower seed layer.