Magnetic recording medium, production process thereof, and magnetic recording and reproducing apparatus
AssigneeShowa Denko K.K.
InventorsKenzo Hanawa, Toshinori Asaumi
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Abstract
An object of the present invention is to provide a magnetic recording medium exhibiting excellent magnetic characteristics, such as coercive force. On a substrate, a Cr-containing non-magnetic undercoat film is formed, and a magnetic film of a B-containing Co alloy is formed on the undercoat film. In the vicinity of the interface between the non-magnetic undercoat film and the magnetic film, the amount of Cr is 40 at % or less in a region R1, in which the amount of B is 1 at % or more.
Claims16
A process for producing a magnetic recording medium, comprising
- forming a non-magnetic undercoat film containing Cr on a substrate;
- and
- forming a magnetic film comprising a B-containing Co alloy on the undercoat film, including forming an interface between the non-magnetic undercoat and the magnetic film, wherein the interface contains Cr in an amount of 40 at % or less in a region where B is present in an amount of 1 at % or more.
A process for producing a magnetic recording medium, comprising
- forming a non-magnetic undercoat film on a substrate;
- forming a magnetic film comprising a B-containing Co alloy on the undercoat film, including forming a magnetic film interface layer which contains B in an amount of less than 1 at % and Cr in an amount of 40 at % or less at an upper surface of the layer,
- and forming on the upper surface of the interface layer a magnetic film containing B in an amount of 1 at % or more and Cr in an amount of 40 at % or less.
A process for producing a magnetic recording medium, comprising
- forming a non-magnetic undercoat film containing Cr on a substrate;
- forming a magnetic film comprising a B-containing Co alloy on the undercoat film by depositing a Cr containing alloy containing 40 at % or less Cr and optionally containing B in an amount of less than 1 at %, said depositing forming a mixed layer containing Cr from the undercoat film and Cr from the Cr containing alloy;
- continuing said depositing until the amount of Cr in the mixed layer decreases to 40 at % or less at an upper surface of the mixed layer, and
- then depositing a B-containing Co alloy having a B-content of 1 at % or more.
A process for producing a magnetic recording medium, comprising
- forming a non-magnetic undercoat film containing Cr on the substrate;
- and
- forming a magnetic film on the undercoat film by sputtering a first target comprising at least Co and Cr to form a layer containing 40 at % or less Cr at an upper surface of the layer and sputtering a second target comprising Co and 1 at % or more of B on the upper surface of the layer.
Dependencies are inferred from the claim text.