Abstract: A magnetic recording medium for longitudinal recording with a low media noise, a high S/N ratio and high reliabilities in corrosion resistance is disclosed. By making a magnetic layer from a Co-based alloy comprising 1 to 35 at. % of at least one element selected from the group consisting of Pt and Ir, 1 to 17 at. % of at least one element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Ge and Si, except for Si, whose concentration is 1 to 40 at. and 0.1 to 10 at. of oxygen, a magnetic recording medium for longitudinal recording having an inplane coercivity of 1,200 Oe or more and a coercive squares of not more than 0.85 is obtained. A process for producing the magnetic recording medium for longitudinal medium and a magnetic memory apparatus using the magnetic recording medium for longitudinal recording are also disclosed.

Abstract: A magnetic recording medium including a substrate and a magnetic layer on the substrate which is a Co-based alloy including Pt and/or Ir, including at least one of Ti, Zr, Hr, V, Nb, Ta, Cr, Mo, W, Ge, and Si, and including oxygen. A magnetic memory apparatus including the magnetic recording medium.

Abstract: A magnetic recording medium for longitudinal recording with a low media noise, a high S/N ratio and high reliabilities in corrosion resistance is disclosed. By making a magnetic layer from a Co-based alloy comprising 1 to 35 at. % of at least one element selected from the group consisting of Pt and Ir, 1 to 17 at. % of at least one element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Ge and Si, except for Si, whose concentration is 1 to 40 at. %, and 0.1 to 10 at. % of oxygen, a magnetic recording medium for longitudinal recording having an inplane coercivity of 1,200 Oe or more and a coercive squares of not more than 0.85 is obtained.

Abstract: A magnetic disk includes a substrate, a magnetic layer, and a protective layer. At least one region of a surface of the magnetic disk has protrusions. A height of each of the protrusions is not less than 5 nm and not greater than 40 nm, and is within ±30% of an average height of the protrusions. A density of the protrusions is not less than 200/mm2 and is not greater than 250,000/mm2. A width of a surface of each of the protrusions in a radial direction of the magnetic disk is not less than 0.1 &mgr;m and is not greater than 10 &mgr;m. The protrusions are discrete protrusions aligned in a spiral direction of the magnetic disk at a predetermined spacing in the radial direction of the magnetic disk. The at least one region of the surface of the magnetic disk includes flat areas between the protrusions.

Abstract: In a magnetic recording medium having a non-magnetic disk substrate and a magnetic film formed on the surface of the non-magnetic disk substrate, a surface average roughness factor Ra(r) on the surface of the medium being from 0.3 nm to 3 nm, an orientation ratio of coercivity being from 0.1 to 0.7, and an in-plane magnetic anisotropic energy being from 3.times.10.sup.4 J/m.sup.3 to 5.times.10.sup.5 J/m.sup.3. By using such a medium, it is possible to provide a magnetic recording apparatus in which the magnetic head is capable of flying in a low position and high-density recording is achieved.

Abstract: A magnetic recording medium including a substrate and a magnetic layer on the substrate which is a Co-based alloy including Pt and/or Ir, including at least one of Ti, Zr, Hr, V, Nb, Ta, Cr, Mo, W, Ge, and Si, and including oxygen. A magnetic memory apparatus including the magnetic recording medium.

Abstract: There is provided a magnetic disk apparatus comprising: at least one magnetic disk having a magnetic layer and a surface protective layer on a substrate; a magnetic head which faces the magnetic disk in a rotating state with a micro gap and is supported by a slider; rotating means for rotating the magnetic disk; and a actuator for moving and positioning the magnetic head to a predetermined position on the magnetic disk, wherein a plurality of protrusions each having a flat surface are formed in at least a region on the surface of the magnetic disk where a contact start/stop operation can be executed. According to the above magnetic disk apparatus, since the frictional force between the disk and the head is small and the flying height of the head can be reduced and the good floating stability is obtained, so that the excellent recording and reproducing characteristics are derived.

Abstract: In a magnetic recording medium having a nonmagnetic disk substrate and a magnetic film formed on the surface of the non-magnetic disk substrate, a surface average roughness factor Ra(r) on the surface of the medium being from 0.3 nm to 3 nm, an orientation ratio of coercivity being from 0.1 to 0.7, and an in-plane magnetic anisotropic energy being from 3.times.10.sup.4 J/m.sup.3 to 5.times.10.sup.5 J/m.sup.3. By using such a medium, it is possible to provide a magnetic recording apparatus in which the magnetic head is capable of flying in a low position and high-density recording is achieved.

Abstract: A magnetic recording medium for longitudinal recording with a low media noise, a high S/N ratio and high reliabilities in corrosion resistance is disclosed. By making a magnetic layer from a Co-based alloy comprising 1 to 35 at. % of at least one element selected from the group consisting of Pt and Ir, 1 to 17 at. % of at least one element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Ge and Si, except for Si, whose concentration is 1 to 40 at. %, and 0.1 to 10 at. % of oxygen, a magnetic recording medium for longitudinal recording having an inplane coercivity of 1,200 Oe or more and a coercive squares of not more than 0.85 is obtained.

Abstract: A magnetic disk has a magnetic layer and a protective layer disposed on the magnetic layer. A multiplicity of lands having sizes within a predetermined range of sizes and generally equal heights within a predetermined range are formed on the surface of the protective layer at a density within a predetermined range. The lands serve to effectively remove contaminants attached to the floating surface of a magnetic head to ensure a desired sliding reliability and floating stability of the head during a long period of time even in the case of a high-density magnetic disk apparatus in which the extent of floating of the head is small. The reliability with which the magnetic disk apparatus operates is thereby improved. The lands are formed on the surface of the protective layer by a process of forming a mask of fine particles on the protective layer surface and etching the protective layer surface through this mask.

Abstract: There is provided a magnetic disk apparatus comprising: at least one magnetic disk having a magnetic layer and a surface protective layer on a substrate; a magnetic head which faces the magnetic disk in a rotating state with a micro gap and is supported by a slider; rotating means for rotating the magnetic disk; and a actuator for moving and positioning the magnetic head to a predetermined position on the magnetic disk, wherein a plurality of protrusions each having a flat surface are formed in at least a region on the surface of the magnetic disk where a contact start/stop operation can be executed. According to the above magnetic disk apparatus, since the frictional force between the disk and the head is small and the flying height of the head can be reduced and the good floating stability is obtained, so that the excellent recording and reproducing characteristics are derived.

Abstract: The present invention provides a magnetic recording medium wherein the surface layer of the protective film of the medium is irradiated by ions to give a protective film having high reliability in resistance to sliding with the magnetic head, a process for producing the medium, an apparatus for producing the medium, and a magnetic recording apparatus having the medium mounted therein. The essentials of the present invention lie in introducing a minute surface roughness of atomic order in the surface of the protective film 5 constituting the outermost layer of a magnetic recording medium by irradiating atoms accelerated by high voltage (that is, by implanting ions) to the surface.

Abstract: A method of forming projections on major surfaces of a disk comprises the steps of supporting the disk in a space, spraying a multiplicity of fine solid particles into the space, charging the sprayed fine solid particles with electricity of the same polarity so that the fine solid particles are floating in the space in a mutually separated state due to electric repellent forces acting between the fine solid particles, electrostatically depositing the fine solid particles charged with electricity on the surfaces of the disk, and etching the disk surfaces by using the deposited fine solid particles as masks, thereby forming a multiplicity of projections on the disk surfaces.

Abstract: A magnetic disk includes a non-magnetic substrate with a surface processed layer having fine irregularities formed at least on a main surface thereof, and at least a thin film magnetic film and a protective film formed in that order on the non-magnetic substrate in such a manner that the fine irregularities are duplicated thereof. The surface of the surface processed layer of the non-magnetic substrate has protrusions whose surfaces are made flat and a configuration which exhibits a three-dimensional bearing curve in which the bearing ratio at a section taken at a depth from the top of the surface which corresponds to the portion of the top portion deformed by the head load during the contact start-stops drive is between 0.1% and 10%. The protrusions formed on the surface processed layer have a height ranging from several nm to several tens of nm. The bearing ratio is a value obtained at a depth of 5 to 10 nm from the top of the protrusions.

Abstract: There is provided a magnetic disk apparatus including at least one magnetic disk having a magnetic layer and a surface protective layer on a substrate; a magnetic head which faces the magnetic disk in a rotating state with a micro gap and is supported by a slider; rotating means for rotating the magnetic disk; and magnetic head positioning means for moving and positioning the magnetic head to a predetermined position on the magnetic disk, wherein a plurality of protrusions each having a flat surface are formed in at least a region on the surface of the magnetic disk where a contact start/stop operation can be executed, an area ratio of the protrusions per 1 mm.sup.2 lies within a range from 0.1 to 80%, a height of the protrusion of the maximum height among the protrusions lies within a range from 5 to 40 nm, and the magnetic layer is formed on the whole surface on the base plate.

Abstract: The magnetic recording medium includes a nonmagnetic substrate having different values of surface tension corresponding to surface free energy in a predetermined magnetic recording direction and in the direction substantially perpendicular thereto, a magnetic film epitaxially grown on the nonmagnetic substrate, and a protective film on the magnetic film. The surface of the nonmagnetic substrate is provided with irregular surfaces having gradients of 45 degrees .+-.10 degrees relative to the substrate surface. The magnetic film has a main component of an easy axis of magnetization in the magnetic recording direction. The hydrogen peroxide aqueous solution and nitric acid used for the surface treatment of the substrate affect differently the critical surface tension. The partial nonmetal layer can be partially worked to provide textures extending in the magnetic recording direction.

Abstract: A disk-type recording medium having a circular substrate on which a recording layer is formed does not include any through hole formed in the center of rotation. Since no through hole is formed, it is possible to improve the reliability of the medium with regard to its strength, and to reduce the thickness of the substrate. Further, it is possible to render the thickness of the recording coating uniform.

Abstract: A magnetic recording medium that uses, as a protective coating layer provided on a magnetic layer for magnetically recording signals, a layer made of a nonmagnetic material consisting of two ore more elements of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, and W, and one or more elements of N, C, O, and B, or made of a magnetic material consisting of one or more elements of Co, Fe, Ni, and Gd, one or more elements of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, and W, and one or more elements of N, C, O, B, and Si is excellent in sliding endurance. When the protective coating layer is made of the nonmagnetic material, the magnetic recording medium is also excellent in corrosion resistance, and when the protective coating layer is made of the magnetic material, the spacing between a magnetic head and the magnetic recording medium can advantageously be made large. Both the cases are high in reliability, and suitable for high density magnetic recording.

Abstract: A magnetic disk includes a non-magnetic substrate with a surface processed layer having fine irregularities formed at least on a main surface thereof, and at least thin film magnetic film and a protective film formed in that order on the non-magnetic substrate in such a manner that the fine irregularities are duplicated thereof. The surface of the surface processed layer of the non-magnetic substrate has protrusions whose surfaces are made flat and a configuration which exhibits a three-dimensional bearing curve in which the bearing ratio at a section taken at a depth from the top of the surface which corresponds to the portion of the top portion deformed by the head load during the contact start-stops drive is between 0.1% and 10%. The protrusions formed on the surface processed layer have a height ranging from several nm to several tens of nm. The bearing ratio is a value obtained at a depth of 5 to 10 nm from the top of the protrusions.

Abstract: A thin film magnetic head for performing recording and readout operations to a magnetic recording medium and a method of manufacturing the head. The magnetic head .[.comprises.]. .Iadd.includes .Iaddend.a substrate, a first magnetic layer formed on the substrate, a conductor coil on the first layer and a second magnetic layer formed on the conductor coil and the first magnetic layer. The second magnetic layer is imparted with a greater thickness than the first magnetic layer to thereby strengthen the magnetic field for recording and reducing the peak shift making appearance in readout operation due to interference between successively read-out waveforms. The thin film magnetic head exhibits an improved reproduction characteristic which permits reproduction with high fidelity the magnetized locations recorded on the medium with high recording density which assures an improved recording characteristic. .Iadd.