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Perpendicular magnetic recording medium and hard disk drive using the same

  • US 20080180843A1
  • Filed: 01/17/2008
  • Published: 07/31/2008
  • Est. Priority Date: 01/18/2007
  • Status: Active Grant
First Claim
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1. A perpendicular magnetic recording medium comprising a substrate, a magnetic recording layer and a protective layer, whereinthe magnetic recording layer includes a perpendicular recording layer, a magnetic coupling layer and a writing assist layer;

  • the perpendicular recording layer is a Co alloy layer containing an oxide disposed between the magnetic coupling layer and the substrate;

    the magnetic coupling layer is a ferromagnetic layer disposed between the perpendicular recording layer and the writing assist layer;

    the writing assist layer is a ferromagnetic layer disposed between the magnetic coupling layer and the protective layer;

    the saturation magnetization of the magnetic coupling layer is lower than the saturation magnetization of the perpendicular recording layer or the writing assist layer; and

    the thickness of the magnetic coupling layer is 1 nm or more and 3 nm or less.

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