Patent ID: 7618722
Filing Date: 2009-11-17
Classification: G11B

Abstract:
1. A perpendicular magnetic recording medium having at least a soft-magnetic underlayer, a first intermediate layer, a second intermediate layer, a third intermediate layer, and a magnetic recording layer successively formed on a substrate, wherein: said first intermediate layer is composed of any of the metals of Ti, Zr, and Hf or a non-magnetic alloy whose main component is at least one of Ti, Zr, and Hf having a hexagonal close-packed (hcp) structure; said second intermediate layer is composed of any of the metals of Al, Ag, Au, Cu, Ni, and Pd or an alloy whose main component is at least one of Al, Ag, Au, Cu, Ni, and Pd; said third intermediate layer is composed of Ru or an Ru alloy; and said magnetic recording layer is composed of ferromagnetic grains and of oxides or nitrides.