Patent ID: 7687157
Filing Date: 2010-03-30
Classification: G11B

Abstract:
1. A recording medium for perpendicular recording applications, the recording medium comprising: a substrate; a magnetic recording layer having a first coercivity and an axis of magnetic anisotropy substantially perpendicular to the surface thereof; an exchange-spring layer having a second coercivity less than the first coercivity, the exchange-spring layer ferromagnetically exchange coupled to the magnetic recording layer, the magnetic recording layer disposed between the substrate and the exchange-spring layer; a coupling layer between the magnetic recording layer and the exchange-spring layer, the coupling layer regulating the ferromagnetic exchange coupling between the magnetic recording layer and the exchange-spring layer, the coupling layer adjusted such that a magnetization of the exchange-spring layer begins to reverse before a magnetization of the magnetic recording layer, the magnetization of the exchange-spring layer exerting a torque on the magnetic recording layer such that the magnetization of the magnetic recording layer follows the magnetization of the exchange-spring layer, wherein the magnetization of the magnetic recording layer begins to reverse before the magnetization of the exchange-spring layer completely reverses; and wherein the magnetic recording layer and the exchange-spring layer both comprise cobalt alloys.