Perpendicular magnetic recording medium and magnetic storage apparatus
AssigneeFujitsu Limited
InventorTakashi Gouke
Life of this patent
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Abstract
A perpendicular magnetic recording medium is provided with a substrate, a soft magnetic back layer provided on a surface of the substrate, an orientation controlling underlayer provided on the soft magnetic back layer, and a recording layer provided above the orientation controlling underlayer and having axes of easy magnetization approximately perpendicular to the surface of the substrate. The recording layer is made of a ferromagnetic material having an hcp crystal structure. The orientation controlling underlayer is made of a nonmagnetic material having an fcc crystal structure and having NiCr or NiCu as a main component.
Claims18
A perpendicular magnetic recording medium comprising:
- a substrate;
- a soft magnetic back layer provided on a surface of the substrate;
- an orientation controlling underlayer provided on the soft magnetic back layer;
- and
- a recording layer provided above the orientation controlling underlayer and having axes of easy magnetization approximately perpendicular to the surface of the substrate,
- wherein the recording layer is made of a ferromagnetic material having an hcp crystal structure,
- the orientation controlling underlayer is made of a nonmagnetic material having an fcc crystal structure and having NiCu as a main component and a Cu content in a range of 40 at. % to 99 at. %, and
- the soft magnetic back layer has a stacked ferrimagnetic structure made up of a pair of soft magnetic layers that are antiferromagnetically exchange-coupled via a Ru layer.
A magnetic storage apparatus comprising:
- at least one perpendicular magnetic recording medium comprising a substrate, a soft magnetic back layer provided on a surface of the substrate and having a stacked ferrimagnetic structure made up of a pair of soft magnetic layers that are antiferromagnetically exchange-coupled via a Ru layer, an orientation controlling underlayer provided on the soft magnetic back layer, and a recording layer provided above the orientation controlling underlayer and having axes of easy magnetization approximately perpendicular to the surface of the substrate, wherein the recording layer is made of a ferromagnetic material having an hcp crystal structure, and the orientation controlling underlayer is made of a nonmagnetic material having an fcc crystal structure and having NiCu as a main component and a Cu content in a range of 40 at. % to 99 at. %;
- and
- a head comprising a recording element and a reproducing element, and configured to record information on the perpendicular magnetic recording medium by the recording element and to reproduce information from the perpendicular magnetic recording medium by the reproducing element.
Dependencies are inferred from the claim text.