Patent ID: 9183869
Filing Date: 2015-11-10
Classification: G11B

Abstract:
1. A method of manufacturing a perpendicular magnetic recording medium including at least a ground layer, a non-magnetic granular layer, a first magnetic recording layer, and a second magnetic recording layer in this order on a base, comprising: forming the first magnetic recording layer using a magnetic target that includes, in a composition, any of chrome, oxygen, or an oxide, or a plurality of oxides, and a gas pressure of approximately 0.5 Pa and a power of approximately 100 to approximately 700 W are set, thereby forming a ferromagnetic layer of a granular structure in which non-magnetic grain boundary parts are formed each between crystal grains each grown in a columnar shape, forming the second magnetic recording layer using a magnetic target that includes, in a composition, any of chrome, oxygen, or an oxide, or a plurality of oxides, and where a gas pressure of approximately 0.5 Pa and a power of approximately 100 to approximately 1000 W are set, wherein the second magnetic recording layer is a ferromagnetic layer of a granular structure in which non-magnetic grain boundary parts are formed each between crystal grains each grown in a columnar shape, and wherein A<B when an average particle diameter of the crystal grains in the first magnetic recording layer is taken as A nm and an average particle diameter of the crystal grains in the second magnetic recording layer is taken as B nm, and the average particle diameter of the non-magnetic granular layer is smaller than the average particle diameter of the first magnetic recording layer.