Magnetic recording medium, process for producing the same and magnetic disk device
First Claim
1. A magnetic recording medium having a recording layer of a magnetic material composed mainly of cobalt and formed on a multi-layered underlayer formed on a substrate, the multi-layered underlayer comprising:
- a first underlayer of a nonmagnetic material composed mainly of chromium;
an epitaxially grown second underlayer of an antiferromagnetic material, with a body-centered cubic structure, having a Neel temperature of at least 60°
C., the second underlayer being such that a length of a side of the lattice in the (100) face of the crystal lattice of the antiferromagnetic material is approximately equal to a length of a diagonal of the lattice in the (100) face of the crystal lattice in the body-centered cubic structure of the first underlayer, the recording layer being formed in direct contact with said second underlayer.
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Accused Products
Abstract
A magnetic recording medium characterized by comprising: a nonmagnetic substrate; and, provided on the nonmagnetic substrate in the following order, a first underlayer of a nonmagnetic material composed mainly of chromium, a second underlayer of an antiferromagnetic material, with a body-centered cubic structure, having a Neel temperature of at least 60° C., the second underlayer being such that, when the crystal lattice of the antiferromagnetic material is compared with the crystal lattice in the body-centered cubic structure of the first underlayer, the length of a side of the lattice in the (100) face of the former is approximately equal to the length of a diagonal of the lattice in the (100) face of the latter, permitting the second underlayer to be epitaxially grown onto the first underlayer, and a recording layer of a magnetic material composed mainly of cobalt.
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Citations
10 Claims
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1. A magnetic recording medium having a recording layer of a magnetic material composed mainly of cobalt and formed on a multi-layered underlayer formed on a substrate, the multi-layered underlayer comprising:
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a first underlayer of a nonmagnetic material composed mainly of chromium; an epitaxially grown second underlayer of an antiferromagnetic material, with a body-centered cubic structure, having a Neel temperature of at least 60°
C., the second underlayer being such that a length of a side of the lattice in the (100) face of the crystal lattice of the antiferromagnetic material is approximately equal to a length of a diagonal of the lattice in the (100) face of the crystal lattice in the body-centered cubic structure of the first underlayer, the recording layer being formed in direct contact with said second underlayer. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A process for producing a magnetic recording medium, which comprises sputtering a first underlayer of a nonmagnetic material composed mainly of chromium, a second underlayer of an antiferromagnetic material formed on said first underlayer and having a Neel temperature of at least 60°
- C., and a recording layer of a magnetic material composed mainly of cobalt formed directly on said second underlayer, in the recited order, on a nonmagnetic substrate.
- View Dependent Claims (8)
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9. A magnetic disk device comprising:
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a recording head section for recording information in a magnetic recording medium; a reproducing head section for reproducing information with a magnetoresistive head, the magnetic recording medium having a recording layer of a magnetic material composed mainly of cobalt and formed on a multi-layered underlayer formed on a substrate, the multi-layered underlayer including; a first underlayer of a nonmagnetic material composed mainly of chrornium; an epitaxially grown second underlayer of an antiferromagnetic material, with a body-centered cubic structure, having a Neel temperature of at least 60°
C., the second underlayer being such that a length of a side of the lattice in the (100) face of the crystal lattice of the antiferromagnetic material is approximately equal to a length of a diagonal of the lattice in the (100) face of the crystal lattice in the body-centered cubic structure of the first underlayer, the recording layer being formed in direct contact with said second underlayer. - View Dependent Claims (10)
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Specification