Abstract: A glass substrate for perpendicular magnetic recording, having a surface with an average surface roughness of 2.0? or less and surface height variations of 1? or less with wavelengths in the range of 0.05 mm-0.5 mm in both radial and circumferential directions, is produced by rotating a glass substrate, supplying polishing slurry containing a specified amount of abrading particles of artificial diamond on its surface, pressing a polishing tape on the surface and causing this polishing tape to travel in a direction opposite to the direction of rotation of the glass substrate.

Abstract: A method of texturing a surface of a magnetic hard disk substrate includes the steps of rotating the magnetic hard disk substrate, supplying polishing slurry on the surface of the substrate, and pressing a polishing tape on the substrate surface and running the polishing tape. The polishing slurry includes abrading particles of monocrystalline diamond that are cluster particles with corners having diameters in the range of 1-10 nm, dispersed in a dispersant such as water and a water-based aqueous solution. The cluster particles are tasseled assemblies of crystalline particles with no directionality.

Abstract: A glass substrate for perpendicular magnetic recording, having a surface with an average surface roughness of 2.0 ? or less and surface height variations of 1 ? or less with wavelengths in the range of 0.05 mm-0.5 mm in both radial and circumferential directions, is produced by rotating a glass substrate, supplying polishing slurry containing a specified amount of abrading particles of artificial diamond on its surface, pressing a polishing tape on the surface and causing this polishing tape to travel in a direction opposite to the direction of rotation of the glass substrate.

Abstract: A method of texturing a surface of a magnetic hard disk substrate includes the steps of rotating the magnetic hard disk substrate, supplying polishing slurry on the surface of the substrate, and pressing a polishing tape on the substrate surface and running the polishing tape. The polishing slurry includes abrading particles of monocrystalline diamond that are cluster particles with corners having diameters in the range of 1-10 nm, dispersed in a dispersant such as water and a water-based aqueous solution. The cluster particles are tasseled assemblies of crystalline particles with no directionality.

Abstract: A perpendicular magnetic recording disk is produced by forming a soft magnetic layer on a non-magnetic substrate either directly or through a foundation layer in between, forming texturing marks on the surface of this soft magnetic layer, forming a perpendicular magnetic recording layer on the soft magnetic layer either directly or through an intermediate layer in between, and forming a protective layer on the perpendicular recording layer. A texturing process is carried out such that the average surface roughness of the soft magnetic layer is 0.5 ?-5.0 ?, and the line density of the texturing marks is 30 lines/?m or more.

Abstract: Texturing line marks are formed clearly and uniformly over a surface of a glass substrate for a magnetic hard disk such that there will be no abnormal protrusions exceeding 100 ? and the line density will be 30 lines/?m or more by rotating the glass substrate, supplying slurry on the surface of the glass substrate and pressing a processing tape on the surface of the glass substrate and running the processing tape. The slurry includes abrading particles of an artificial diamond material produced by a shock method and dispersed in a dispersing medium. The abrading particles include primary particles that are artificial diamond particles with average diameter 1 nm-20 nm and cluster particles with secondary particles that are artificial diamond particles with average diameter 0.05 ?m-0.20 ?m. The dispersing medium of the slurry includes water and an additive that contains higher aliphatic amide and two or more selected from the group consisting of glycol compounds, organic phosphates and surfactants.

Abstract: A magnetic hard disk substrate is produced by rotating an aluminum substrate or a glass substrate, supplying polishing slurry on its surface, pressing a polishing tape on the surface and running it in a direction opposite to the direction of rotation of the substrate. Texturing marks are formed with a line density greater than 70 lines/?m in the radial direction on the surface. The polishing slurry has abrading particles dispersed in a dispersant. The abrading particles may be monocrystalline diamond particles, polycrystalline diamond particles or cluster particles with such monocrystalline and polycrystalline diamond particles with diameters in the range of 1-50 nm. Agglomerated particles of such cluster particles that are agglomerated in the dispersant may also be included as the abrading particles.

Abstract: A magnetic hard disk substrate is produced by rotating an aluminum substrate or a glass substrate, supplying polishing slurry on its surface, pressing a polishing tape on the surface and running it in a direction opposite to the direction of rotation of the substrate. Texturing marks are formed with a line density greater than 70 lines/?m in the radial direction on the surface. The polishing slurry has abrading particles dispersed in a dispersant. The abrading particles may be monocrystalline diamond particles, polycrystalline diamond particles or cluster particles with such monocrystalline and polycrystalline diamond particles with diameters in the range of 1-50 nm. Agglomerated particles of such cluster particles that are agglomerated in the dispersant may also be included as the abrading particles.

Abstract: A glass substrate for perpendicular magnetic recording, having a surface with an average surface roughness of 2.0 ? or less and surface height variations of 1 ? or less with wavelengths in the range of 0.05 mm-0.5 mm in both radial and circumferential directions, is produced by rotating a glass substrate, supplying polishing slurry containing a specified amount of abrading particles of artificial diamond on its surface, pressing a polishing tape on the surface and causing this polishing tape to travel in a direction opposite to the direction of rotation of the glass substrate.

Abstract: A magnetic hard disk substrate is produced by rotating an aluminum substrate or a glass substrate, supplying polishing slurry on its surface, pressing a polishing tape on the surface and running it in a direction opposite to the direction of rotation of the substrate. Texturing marks are formed with a line density greater than 70 lines/&mgr;m in the radial direction on the surface. The polishing slurry has abrading particles dispersed in a dispersant. The abrading particles may be monocrystalline diamond particles, polycrystalline diamond particles or cluster particles with such monocrystalline and polycrystalline diamond particles with diameters in the range of 1-50 nm. Agglomerated particles of such cluster particles that are agglomerated in the dispersant may also be included as the abrading particles.

Abstract: Polishing slurry for texturing the surface of a magnetic hard disk substrate has abrading particles with diameters in the range of 1-10 nm dispersed in a dispersant such as water and a water-based aqueous solution. The abrading particles may be monocrystalline diamond particles, polycrystalline diamond particles or cluster particles with monocrystalline and polycrystalline diamond particles. A method of texturing a surface of a magnetic hard disk substrate includes the steps of rotating the magnetic hard disk substrate, supplying polishing slurry of this invention on the surface of the substrate, and pressing a polishing tape on the substrate surface and running the polishing tape.

Abstract: Slurries to be supplied to the surface of a rotating glass substrate for texturing the surface to create streaks contain aggregates having diameters not larger than 0.51 &mgr;m of polycrystalline diamond particles that are dispersed in water or a water-based aqueous solution that is free of any substance having an etching effect on a glass material. A glass substrate is textured by supplying such a slurry material on its surface as the substrate is rotated and a polishing tape is pressed and run against the substrate surface.