Perpendicular magnetic recording medium and magnetic recording apparatus
AssigneeFujitsu Limited
InventorAntony Ajan
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Abstract
A disclosed perpendicular magnetic recording medium includes a substrate; a soft magnetic underlayer disposed on the substrate and having no remanent magnetization; and a ferromagnetic recording layer disposed on the soft magnetic underlayer. The soft magnetic underlayer includes at least three soft magnetic layers laid one above the other with a non-magnetic intermediate layer interposed between every two adjacent soft magnetic layers. Among the (at least) three soft magnetic layers, at least one pair of soft magnetic layers form ferromagnetic coupling. Among the (at least) three soft magnetic layers, at least one pair of soft magnetic layers form antiferromagnetic coupling.
Claims10
A perpendicular magnetic recording medium comprising:
- a substrate;
- a soft magnetic underlayer disposed on the substrate and having no remanent magnetization;
- and
- a ferromagnetic recording layer disposed on the soft magnetic underlayer;
- wherein the soft magnetic underlayer includes at least three soft magnetic layers laid one above the other with a non-magnetic intermediate layer interposed between every two adjacent soft magnetic layers,
- among the (at least) three soft magnetic layers, at least one pair of soft magnetic layers form ferromagnetic coupling, and
- among the (at least) three soft magnetic layers, at least one pair of soft magnetic layers form antiferromagnetic coupling.
A magnetic recording apparatus comprising:
- a perpendicular magnetic recording medium;
- a magnetic head configured to scan the perpendicular magnetic recording medium;
- and
- a driving system configured to cause the magnetic head to scan the perpendicular magnetic recording medium;
- wherein the perpendicular magnetic recording medium includes a substrate, a soft magnetic underlayer disposed on the substrate and having no remanent magnetization, and a ferromagnetic recording layer disposed on the soft magnetic underlayer,
- the soft magnetic underlayer includes at least three soft magnetic layers laid one above the other with a non-magnetic intermediate layer interposed between every two adjacent soft magnetic layers, and
- among the (at least) three soft magnetic layers, at least one pair of soft magnetic layers form ferromagnetic coupling, and
- among the at least three soft magnetic layers, at least one pair of soft magnetic layers form antiferromagnetic coupling.
Dependencies are inferred from the claim text.