Patent ID: 7732070
Filing Date: 2010-06-08
Classification: G11B

Abstract:
1. A perpendicular magnetic recording medium, comprising: a substrate; a soft magnetic underlayer formed on the substrate; a seed layer of an amorphous material formed on the soft magnetic underlayer; an oxidation prevention layer formed on the seed layer; an underlayer formed on the oxidation prevention layer, the underlayer including a plurality of crystal grains formed of one of Ru and a Ru alloy having an hcp crystal structure, and a first air gap part configured to separate the crystal grains from each other; and a recording layer formed on the underlayer, the recording layer including a plurality of magnetic particles having a magnetocrystalline easy axis in a direction substantially perpendicular to a surface of the substrate, and one of a second air gap part and a non-magnetic non-solid-solution phase, the one being configured to separate the magnetic particles from each other, wherein the oxidation prevention layer includes a noble metal element other than Ru, the noble metal element being Pt.