Perpendicular magnetic recording medium with epitaxial exchange coupling layer

摘要

FePt-based perpendicular magnetic recording (PMR) media including an epitaxial exchanged coupling layer (EECL) between FePtX magnetic recording layers. The degree of exchange coupling may be modulated by the EECL while the texture is transferred between the magnetic recording layers. With an EECL of proper composition and thickness, the FePt-based composite media has high anisotropy field and low saturation magnetic field.

主权项

1. A recording medium for perpendicular recording applications, the recording medium comprising:
a substrate; a soft underlayer on the substrate; an exchange break layer consisting of a nucleation layer directly on the soft underlayer and an intermediate layer, wherein the nucleation layer consists of CrRu with a (002) crystal structure and the intermediate layer consists of MgO with a (001) crystal structure; and a composite recording layer directly on the intermediate layer of the exchange break layer and comprising:
a first magnetic recording layer comprising a first FePtX alloy and having an axis of magnetic anisotropy substantially perpendicular to a surface thereof;an exchange-spring layer comprising a second FePtX alloy and having a coercivity less than that of the first magnetic recording layer, the exchange-spring layer ferromagnetically exchange coupled to the first magnetic recording layer; anda coupling layer between the first magnetic recording layer and the exchange-spring layer, the coupling layer configured to regulate the ferromagnetic exchange coupling between the first magnetic recording layer and the exchange-spring layer and to transfer an epitaxial growth from the first magnetic recording layer to the exchange-spring layer, wherein the exchange break layer is configured to magnetically decouple the soft underlayer from the composite recording layer, wherein the coupling layer consists of Pt with a (001) crystal structure, and wherein a change in a c-axis lattice constant between the first magnetic recording layer and the exchange-spring layer is less than 3%.