Invention Grant
US08647755B2 Perpendicular magnetic recording medium and manufacturing method thereof 有权
垂直磁记录介质及其制造方法

Perpendicular magnetic recording medium and manufacturing method thereof
Abstract:
Embodiments of the present invention provide a perpendicular magnetic recording medium with less medium noise, excellent overwrite characteristics, and scratch resistance. According to one embodiment, when an Ar gas with addition of a micro-amount of oxygen is used upon forming an upper Ru intermediate layer, a micro-structure of a magnetic layer formed thereon can be formed in a state where no magnetic oxide region is segregated and the magnetic crystal grains are isolated. In this case, a gas pressure for forming the upper intermediate layer is set to 5 Pa or more and 12 Pa or less which is a region much higher compared with 0.5 Pa or more and 1 Pa for the lower Ru intermediate layer. Since writing by a head becomes difficult remarkably in the perpendicular magnetic medium having magnetic crystal grains promoted for isolation, a second magnetic layer for facilitating magnetization reversal by lowering the oxide concentration and somewhat strengthening coupling between particles only in the magnetic layer on the side of the surface is formed to a layer above the first magnetic layer as a main part.
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