Abstract: In a magnetic disk having at least a glass substrate, a plurality of underlayers formed over the glass substrate, and a magnetic layer formed over the plurality of underlayers, at least one of the underlayers is an amorphous underlayer containing a VIa group element and carbon and, given that the remanent magnetization in a circumferential direction of the disk is Mrc and the remanent magnetization in a radial direction of the disk is Mrr, the magnetic disk has a magnetic anisotropy in which Mrc/Mrr being a ratio between Mrc and Mrr exceeds 1.

Abstract: In a magnetic disk having at least a glass substrate, a plurality of underlayers formed over the glass substrate, and a magnetic layer formed over the plurality of underlayers, at least one of the underlayers is an amorphous underlayer containing a VIa group element and carbon and, given that the remanent magnetization in a circumferential direction of the disk is Mrc and the remanent magnetization in a radial direction of the disk is Mrr, the magnetic disk has a magnetic anisotropy in which Mrc/Mrr being a ratio between Mrc and Mrr exceeds 1.

Abstract: In a magnetic disk having a glass substrate, an amorphous underlayer is formed on the glass substrate. A magnetic layer is formed on the amorphous underlayer. The glass substrate is provided with a texture formed to induce magnetic anisotropy in the magnetic layer. The amorphous underlayer contains a group IVa element on a glass substrate side and a group Va element on a magnetic layer side.

Abstract: A magnetic disk 10 has a disk substrate 1 and an exchange coupling film 5 which is formed thereon and which has a first magnetic layer 5a, a second magnetic layer 5c, and a spacer layer 5b interposed between the first and the second magnetic layers 5a and 5c. The spacer layer 5b has a surface roughness Ra not greater than the thickness of the spacer layer 5b, where Ra is representative of a center-line-mean roughness.

Abstract: In a magnetic disk having a glass substrate, an amorphous underlayer is formed on the glass substrate. A magnetic layer is formed on the amorphous underlayer. The glass substrate is provided with a texture formed to induce magnetic anisotropy in the magnetic layer. The amorphous underlayer contains a group IVa element on a glass substrate side and a group Va element on a magnetic layer side.

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: 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: A magnetic recording medium comprises a non-magnetic substrate having a principal surface, an intermediate layer formed on the principal surface, and a magnetic layer formed on the intermediate layer. The intermediate layer comprises an intermediate material composed of chromium and molybdenum. The magnetic layer comprises a magnetic material composed of cobalt and platinum. The intermediate layer may comprise first and second layers. The first layer comprises a first material composed of chromium and is formed on the principal surface. The second layer comprises a second material composed of chromium and molybdenum and is formed on the first layer.

Abstract: In a magnetic recording medium having an underlying film of a body-centered-cubic (bcc) CrV-based alloy and a magnetic film of a hexagonal close-packed (hcp) CoPtCr-based alloy deposited on the underlying film, a difference between a crystal lattice plane distance d.sub.(002) of (002) planes in the hcp alloy of the magnetic film and another crystal lattice plane distance d.sub.(110) of (110) planes in the bcc alloy of the nonmagnetic film is given by subtracting d.sub.(110) from d.sub.(002) and falls within a range between 0.002 and 0.032 angstrom. Preferably, the difference d.sub.(002) -d.sub.(110) is present between 0.014 and 0.030 angstrom only a single pair of the underlying film and the magnetic film may be included in the magnetic recording medium or plural pairs of the underlying film and the magnetic film may be included in the magnetic recording medium.

Abstract: A method of manufacturing a magnetic recording medium by using an in-line sputtering apparatus to successively form, on a substrate, at least one underlying layer, a first magnetic CoPt-based film, a nonmagnetic intermediate film, and a second magnetic CoPt-based film. The underlying film and/or the nonmagnetic film, which are in contact with the first magnetic film, are deposited at a low sputtering power between 100 and 1000 watts to improve the magnetic properties of the magnetic recording medium. Low power sputtering is also effective to improve the distribution of difference of the crystal lattice spacings between the nonmagnetic intermediate film and the first magnetic film and between the underlying layer and the first magnetic film.

Abstract: Disclosed are magnetic recording media comprising, on a substrate, two or more CrPt based magnetic layers and one or more CrMo based non-magnetic spacer layers between the magnetic layers and processes for preparation thereof. The magnetic recording media of the present invention include magnetic tapes and magnetic disks. The magnetic recording media are capable of suppressing noise generation upon reproducing recorded signals by employing magnetic layers having a small thickness. The magnetic recorders utilizing the above magnetic recording media are also disclosed.

Abstract: A magnetic recording medium comprising a non-magnetic underlayer and a CoPt magnetic layer provided on a substrate in this order wherein the non-magnetic underlayer comprises one or more non-magnetic layers, one of the non-magnetic layers which is in contact with the CoPt magnetic layer consists mainly of Cr and Mo, and difference (d.sub.(002) -d.sub.(110)) obtained by subtracting a crystalline lattice spacing of bcc (110) faces in the non-magnetic layer consisting mainly of Cr and Mo from a crystalline lattice spacing of hcp (002) faces in the magnetic layer falls within a range of from 0.002 to 0.032 .ANG., which shows a high magnetic coercive force and square ratio and a low medium noise, and a method for producing the magnetic recording medium mentioned above wherein at least the non-magnetic layer consisting mainly of Cr and Mo and the CoPt magnetic layer are formed by a sputtering technique using a substrate heating temperature within a range of 250.degree. to 425.degree. C.

Abstract: According to the present invention, a magnetic recording medium comprises a glass substrate, a first under layer, a second under layer, a magnetic layer, a protective layer and a lubricant layer in the named order. The first under layer is formed on a glass plate, a surface of which is highly polished. The second under layer is formed, on the first under layer, of a material differing from a material of the first under layer, and has a thickness greater than a thickness of the first under layer. The magnetic layer is formed on the second under layer. The protective layer is formed on the magnetic layer, on whose surface a texture due to dispersed hard minute particles appears. The lubricant layer is formed on the protective layer.

Abstract: A method of manufacturing a magnetic recording medium by using an in-line sputtering apparatus to successively form, on a substrate, at least one underlying layer, a first magnetic CoPt-based film, a nonmagnetic intermediate film, and a second magnetic CoPt-based film. The underlying film and/or the nonmagnetic film, which are in contact with the first magnetic film, are deposited at a low sputtering power between 100 and 1000 watts to improve the magnetic properties of the magnetic recording medium. Low power sputtering is also effective to improve the distribution of difference of the crystal lattice spacings between the nonmagnetic intermediate film and the first magnetic film and between the underlying layer and the first magnetic film.

Abstract: A metal oxide-type superconductive material is produced by a process which comprises a first step of subjecting a powder raw material containing given proportions of metal elements to be contained in said metal oxide-type superconductive material, to mechanical grinding and alloying simultaneously to obtain an alloy powder and a second step of heat-treating the alloy powder in an oxygen-containing gas atmosphere to obtain a metal oxide.The superconductive material obtained has a high density, a low porosity, a high strength and a high critical current density.