Patent ID: 7498092
Filing Date: 2009-03-03
Classification: G11B

Abstract:
1. A perpendicular magnetic recording medium for use in a system with a perpendicular recording write pole, the medium comprising: a substrate; an underlayer of magnetically permeable material on the substrate as a return path for magnetic flux from the write pole; an exchange break layer on the underlayer; a ferromagnetic write assist layer having an easy axis of magnetization and a magnetization less than about 45 degrees out-of-plane; a ferromagnetic recording layer having perpendicular magnetic anisotropy and an out-of-plane easy axis of magnetization substantially perpendicular to the plane of the recording layer and non-collinear with the easy axis of magnetization of the write assist layer; a nonmagnetic coupling layer between the write assist layer and the recording layer and having a thickness between about 5 Å and 30 Å, the coupling layer being in direct contact with the write assist layer and the recording layer and permitting ferromagnetic coupling of the write assist layer with the recording layer, wherein the write assist layer, coupling layer and recording layer are located on the exchange break layer; and wherein the exchange break layer between the underlayer and the recording layer prevents magnetic exchange coupling between the underlayer and the recording layer.