Abstract: A method of producing a magnetic recording medium by sputtering a layer onto a substrate by DC-magnetron sputtering from a target while exposing the target to an RF signal is described. The RF signal is effective to extend the target utilization without significantly decreasing the sputtering rate. Also disclosed is an apparatus for use forming a medium in accordance with the method of the invention.

Abstract: A sputtering assembly for use in forming sputter deposited layers on a substrate is described. The assembly includes a pair of confronting sputtering targets for depositing sputtered layers onto the substrate and a movably mounted heating means for heating the substrate. A method of using the assembly is also disclosed.

Abstract: A method for forming a magnetic recording medium having a chromium underlayer and a magnetic recording layer is described. The method includes sputtering the underlayer and the magnetic layer in a single sputtering chamber from a two-region target having an inner chromium region and an outer magnetic region. Each target region is successively energized for sputter deposition of each layer.

Abstract: A cathode assembly having a magnetic-field shunt for use in a magnetron sputtering apparatus is described. The magnetic-field shunt disposed between a sputtering target and a source of magnetic flux, and the shunt is moveable between first and second positions to effect preferential target erosion at first and second target regions, respectively. A method of using the assembly for preparation of a magnetic recording medium is also described.

Abstract: A thin-film magnetic recording medium having a carbon overcoat composed of an overcoat sublayer and an overcoat surface layer is described. The overcoat surface layer is a hydrogen- or nitrogen-containing sputtered carbon layer with high wear-resistance. The overcoat sublayer functions to reduce the diffusion of nitrogen or hydrogen from the surface layer to the magnetic recording layer. Also described is a method of sputtering the nitrogen-containing surface layer in which the graphite target is attached to the target electrode by thermally conducting, electrically conducting materials.

Abstract: A shield for use in a sputtering system. The shield includes a support having an inner expanse defining a two-dimensional array of cavities. The cavities are formed of two-dimensionally concave wall surfaces, where the intersections of the wall surfaces of adjacent cavities form a two-dimensional array of edges on the expanse. The shield minimizes the tendency of material deposited on the shield surface, such as sputtered carbon material, from flaking off during a sputtering operation. Also disclosed is a sputtering assembly that employs the shield.

Abstract: A thin-film magnetic recording disc for use with a read/write head in a disc drive is disclosed. To reduce the static and dynamic frictional coefficients of the disc surface, the disc is coated with a lubricant layer composed of a mixture of a polyphenoxycyclotriphosphazene lubricant and a perfluoropolyether oil. Also disclosed is a lubricant composition containing these two components, as well as a method for improving the lubricating properties of a perfluoropolyether oil.

Abstract: A thin-film multilayered recording medium is disclosed. The medium contains two or more magnetic thin-film sublayers separated by an isolation layer having an axial composition gradient.

Abstract: A magnetic thin-film medium having improved magnetic recording properties, including an increased magnetic remanence and high frequency signal amplitude, is disclosed. The magnetic recording medium has a 10-100 .ANG. soft ferromagnetic layer in addition to a substrate, a chromium underlayer, a thin-film magnetic recording layer and a protective overcoat.

Abstract: A longitudinal magnetic recording medium formed on a non-metallic substrate and a method of forming the medium is disclosed. A sublayer formed of a chromium alloy having a thickness between 3-50 .ANG. is deposited on the substrate, followed by a chromium-based underlayer. A cobalt-based magnetic recording layer is sputtered over the underlayer. The medium is characterized by improved coercivity, HF signal amplitude and signal-to-noise ratio.

Abstract: A thin film magnetic disc having a carbon overcoat which is characterized by (i) a surface density of nitrogen atoms between 3-8.times.10.sup.16 atoms/cm.sup.2, as determined by Rutherford backscatter spectroscopy, and (ii) an erosion rate, as measured by rate of erosion of the overcoat by an Al.sub.2 O.sub.3 particle tape placed in contact with the medium, that is several times less than that of a carbon overcoat having the same thickness, but formed by sputtering under a pure argon atmosphere. The overcoat has a preferred thickness between 80-150 .ANG.. Also disclosed is a method of producing a thin, wear-resistant carbon overcoat.

Abstract: A disc-handling apparatus for supporting a magnetic disc during material deposition and for transporting the disc into and out of a deposition station is described. The apparatus has a holder that supports a disc at three contact points by a support and a pair of arms, such that the disc is positively gripped by at least three contact points.

Abstract: An improvement in a magnetic recording disc having a protective overcoat is described. The overcoat extends between an inner-diameter landing zone and a data zone and has a thickness in the landing zone of at least 135 .ANG. and a thickness in the data zone of less than 90 .ANG..

Abstract: A target assembly for use in fabricating magnetic recording media is described. The target assembly has inner and outer concentric targets for sputter depositing on a substrate first and second layers having different compositions. Disposed adjacent each target is a magnetic means, and at least one which is reversible in magnetic-pole polarity. One polarity produces a magnetic flux sufficient to ignite a sputtering plasma in the inner target only, when power is supplied to the inner target at a preselected level. The opposite polarity produces a magnetic flux sufficient to ignite a sputtering plasma in the outer target only, when power is supplied to the outer target at a preselected level.

Abstract: A disc substrate having a selected roughness gradient from an inner-diameter region to an outer-diameter region, and a method of producing the texturing on the substrate are disclosed. The method includes simulating the movement of texturing particles produced by rotating a texturing pad against a rotating disc substrate, at selected substrate and pad rotational speeds and directions, and for a selected run time. Simulation conditions which produce an averaged cross-hatch angle of intersecting texture lines that is at least about 2 times greater at the inner-diameter region of the substrate than at the outer-diameter region are selected.

Abstract: A magnetic thin-film medium formed on a non-metallic substrate and having reduced noise characteristics, by virtue of a 5-50 .ANG., sputtered Cr-containing sublayer interposed between the substrate and a chromium underlayer. Also disclosed is a method of preparing the low-noise medium.

Abstract: A magnetic thin-film media with high coercivity and low noise characteristics is disclosed. The medium has a gradient-composition thin-film magnetic layer in which a lowermost stratum is composed of a first alloy, preferably, having relatively low noise and low magnetic remanence characteristics, and an uppermost stratum composed of a second alloy having relatively high noise and high magnetic remanence characteristics. The medium is characterized by a coercivity which is substantially greater, and a media noise which is substantially less than that of a similar medium whose magnetic thin-film layer is composed of either the first or second alloy alone. Also disclosed is a method of producing such a medium.

Abstract: A mandrel for transporting a plurality of magnetic discs is described. The mandrel has a series of axially spaced grooves, each designed to engage and support a magnetic disc at an inner edge region of the disc's circular opening, at two or more contact positions.

Abstract: A target assembly for use in a magnetron sputtering apparatus having a source of a magnetic field. The apparatus includes an annular sputtering target, and inner and outer poles surrounding the target, defining inner and outer confronting walls which extend beyond the target surface, for conducting magnetic flux across the target. These confronting walls are lined with inner and outer confronting target rings. The annual target and target rings may have different compositions, for use in forming sputtered films with a gradient composition.

Abstract: A magnetic thin-film medium is disclosed. The medium includes a disc-like non-metallic substrate, and a sputtered underlayer having an axial composition gradient in which a lowermost stratum of the layer is a coating metal, such as Ti, V, or W, and an uppermost stratum of the underlayer is Cr. A magnetic thin-film layer is formed on the substrate, and a overcoat is formed on the magnetic layer. Also disclosed is a method of forming the medium.