Magnetic recording medium with a plurality of pinning portions in the magnetic layer

摘要

According to one embodiment, a perpendicular magnetic recording medium includes a substrate, and a multilayered magnetic recording layer formed on the substrate by alternately stacking two or more magnetic layers and two or more nonmagnetic layers. The magnetic layers and nonmagnetic layers of the multilayered magnetic recording layer are continuous layers. The magnetic layer includes a magnetic material portion, and a plurality of pinning sites dispersed in the magnetic material portion and made of a nonmagnetic metal different from a nonmagnetic material as a main component of the nonmagnetic layer. This perpendicular magnetic recording medium has magnetic characteristics by which a gradient α of a magnetization curve near the coercive force is 5 or more.

主权项

1. A perpendicular magnetic recording medium comprising:
a substrate; and a multilayered magnetic recording layer formed on the substrate by alternately stacking not less than two magnetic layers and not less than two nonmagnetic layers, wherein the magnetic layers are each magnetically continuous in an in-plane direction and magnetically coupled with each other, each of the magnetic layers from a bottom of the multilayered magnetic recording layer to a top of the multilayered magnetic recording layer in a thickness direction thereof, includes a magnetic material portion and a plurality of pinning portions, which are capable of pinning magnetic domain walls and dispersed within the magnetic material portion, the pinning portions being metallic and made of a nonmagnetic metal element different from an element that is a main component of the nonmagnetic layer, and a magnetic characteristic of the medium is such that a gradient α of a magnetization curve near a coercive force is not less than 5.