Abstract: A low-noise, thin-film magnetic recording medium, and method of making the same, are disclosed. The medium has a multilayer magnetic-film construction, where the individual magnetic-film layers are isolated by a thin ferromagnetic film. The ferromagnetic layer is effective to reduce the medium noise and increase medium signal-to-noise ratio at least as much as a Cr isolation having the same isolation-layer thickness, but with substantially less reduction in overwrite.

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 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 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 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.

Abstract: A magnetic thin-film disc having a magnetic thin film formed of a lower and upper sublayers. The two sublayers are characterized by lower coercivity, smaller grains, and more isolated grains in the lower sublayer, and higher coercivity, and larger grains in the upper sublayer. In one embodiment, the sublayers are characterized by an increasing magnetic remanence on progressing from the outer to the inner diameter of the disc. Also disclosed are sputtering methods for producing the disc.

Abstract: A target assembly is provided having a circular flat target with an inner ring and an outer ring extending from the sputtering surface. A ferromagnetic outer pole member surrounds the target and the outer ring. A ferromagnetic inner pole member is surrounded by the target and the inner ring. A ferromagnetic backing member is positioned against the base surface of the target and has an outer portion positioned against the outer pole member, and an inner portion positioned against the inner pole member. These are positioned relative to the source of the magnetic field for conducting flux in a first path through the outer portion and the outer pole member, across the sputtering surface between the outer and inner rings, and through the inner pole member and inner portion. The backing member further includes a shunt portion intermediate between and magnetically spaced from the inner and outer portions.

Abstract: A method of forming an isotropic texture having a selected summit density and surface roughness in a selected inner-diameter annular zone of a thin-film medium substrate having a polished metal coating on the substrate. The zone is selectively exposed to a chemical etchant, under etchant strength, temperature, and exposure time, until the selected summit density and roughness are achieved. In a preferred embodiment, the etching conditions are selected to produce a summit density between about 500-20,000/mm.sup.2, and an arithmetic mean roughness value between about 20-70 .ANG. in the inner zone, and a substantially reduced roughness value in an annular, isotropically textured outer-diameter zone of the coating. A thin-film medium formed on the substrate is suitable for near-contact recording.

Abstract: A high-coercivity thin-film magnetic recording medium, and method of producing the medium, is disclosed. The medium has a sputtered chromium underlayer, preferably about 300-1,000 .ANG. thick, and a sputtered magnetic layer, preferably about 200-800 .ANG. thick, composed of an alloy containing between 70-80% cobalt, 10-20% chromium, 3-20% platinum, and 2-10% tantalum, formed on the chromium underlayer. The medium is characterized by high coercivity, resolution, amplitude and loop squareness value, and low bit shift.

Abstract: A high-coercivity thin-film magnetic recording medium, and method of producing the medium, is disclosed. The medium has a sputtered chromium underlayer, preferably about 300-1,000 .ANG. thick, and a sputtered magnetic layer, preferably about 200-800 .ANG. thick, composed of an alloy containing between 70-80% cobalt, 10-20% chromium, 3-20% platinum, and 2-10% tantalum, formed on the chromium underlayer. The medium is characterized by high coercivity, resolution, amplitude and loop squareness value, and low bit shift.

Abstract: A high-coercivity thin-film magnetic recording medium, and method of producing the medium, is disclosed. The medium has a sputtered chromium underlayer, preferably about 600-1,000 .ANG. thick, and a sputtered magnetic layer, preferably about 200-800 .ANG. thick, composed of an alloy containing between 70-80% cobalt, 10-20% chromium, 8-20% platinum, and 2-10% tantalum, formed on the chromium underlayer. The medium is characterized by high coercivity, resolution, amplitude and loop squareness value, and low bit shift.