Abstract: A magnetic recording medium that is high coersive force, hard to receive influence of thermal fluctuation, and brings about a considerable improvement of S/N ratio, and in which at least an underlayer and a magnetic layer are sequentially laminated on a substrate, wherein a pre-coat layer is interposed between said underlayer and said substrate and said pre-coat layer is constructed by sequentially laminating a lower layer containing Ni and P and an upper layer made of a Cr alloy.

Abstract: In a magnetic recording medium which comprises a substrate (1), a magnetic layer (3) formed on the substrate, a carbon-based protection layer (4) comprising carbon and formed on the magnetic layer, and a lubrication layer (5) formed on the carbon-based protection layer, the carbon-based protection layer comprises a hydrogenated carbon protection layer (4a) facing the magnetic layer and a nitrogenated carbon protection layer (4b) facing the lubrication layer. The hydrogenated carbon protection layer (4a) comprises carbon and hydrogen. The nitrogenated carbon protection layer (4b) includes no hydrogen but comprises carbon and nitrogen.

Abstract: In a magnetic recording medium (10) including a glass substrate (1) which has a principal surface and which includes a compressive stress layer (1aa) as a surface layer having the principal surface, and a magnetic layer (4) formed on the principal surface of the glass substrate, compressive stress produced on the principal surface of the glass substrate is equal to 3 kg/mm2 or more. The glass substrate has the principal surface provided with a texture (100) for inducing magnetic anisotropy in the magnetic layer. A distance from the principal surface of the glass substrate to the magnetic layer is equal to 1200 angstroms or less.

Abstract: In a magnetic recording medium including a glass substrate (1) having a principal surface on which at least a magnetic layer (4) is formed, the magnetic recording medium has a coercive force of 2500 oersted or more in a circumferential direction thereof. The principal surface of the glass substrate is provided with a texture having a predetermined surface roughness so that the magnetic layer is given circumferential magnetic anisotropy. The magnetic recording medium further includes a magnetic anisotropy inducing layer (2) formed between the glass substrate and the magnetic layer so that the magnetic recording medium has an oriented ratio (OR) of 1.1 or more. The oriented ratio (OR) is defined as a ratio of a magnetic characteristic in circumferential direction to another magnetic characteristic in the radial direction.

Abstract: In a magnetic recording medium including a substrate (1) having a principal surface on which first and second magnetic layers (5 and 7) and a spacer layer (6) are at least formed, each of the first and the second magnetic layers being of a ferromagnetic material, the spacer layer being formed between the first and the second magnetic layers for inducing antiferromagnetic exchange interaction between the first and the second magnetic layers, the principal surface of the substrate is provided with concentric textures to have a predetermined surface roughness so that the spacer layer has a uniform thickness. The first magnetic layer is for controlling the antiferromagnetic exchange interaction.

Abstract: In a magnetic recording medium which includes a base body (1-4), first and second magnetic layers (5 and 7), each being of a ferromagnetic material, and a spacer layer (6) formed between the first and the second magnetic layers for inducing antiferromagnetic exchange interaction between the first and the second magnetic layers, the second magnetic layer located farther from the base body than the first magnetic layer includes a primary layer (72) and a secondary layer (71) located nearer to the base body than the primary layer. The primary layer has a primary anisotropic magnetic field while the secondary layer has a secondary anisotropic magnetic field which is smaller than the primary anisotropic magnetic field. The first magnetic layer is for controlling the antiferromagnetic exchange interaction.

Abstract: By promoting isolation of magnetic grains in a surface of a magnetic layer and by introducing into the magnetic layer such a construction that includes a magnetic flux circuit easy for a recording magnetic field to penetrate into the magnetic layer of a magnetic recording medium, provided is the magnetic recording medium wherein high coercive force can be obtained, and as well an O/W property and an NLTS property can be enhanced, and an S/N ratio can also be enhanced, and resistance to thermal fluctuation is high, and a conventional tradeoff is avoided, and a manufacturing yield is excellent.

Abstract: A magnetic recording medium that is high coersive force, hard to receive influence of thermal fluctuation, and brings about a considerable improvement of SIN ratio, and in which at least an underlayer and a magnetic layer are sequentially laminated on a substrate, wherein a pre-coat layer is interposed between said underlayer and said substrate and said pre-coat layer is constructed by sequentially laminating a lower layer containing Ni and P and an upper layer made of a Cr alloy.