Abstract: Protective overlayers for magnetic recording media are described. The overlayers, composed of a transition metal-silicon or transition metal-germanium interlayer and a carbon overcoat, provide good wear resistance and corrosion resistance at thicknesses of less than 100 Å.

Abstract: A magnetic recording medium having a dual underlayer structure is described. The underlayer structure is composed of a first underlayer of chromium and a second underlayer of a chromium alloy.

Abstract: Polishing slurries for use in polishing substrates having a nickel or nickel-containing surface, such as those used for magnetic media, are described. The slurries include, in addition to a chemical etchant such as aluminum nitrate and suspended abrasive particles, an oxidizer which converts nickel metal at the surface to nickel oxide, but does not solubilize the nickel oxide in the aqueous medium to any significant degree. Preferred oxidizers include hydrogen peroxide, ferric nitrate and potassium iodate.

Abstract: A longitudinal magnetic recording medium having a CrTi underlayer deposited under a substrate bias is described. The medium has improved magnetic recording properties.

Abstract: A magnetic recording medium having a barrier layer deposited directly on the magnetic recording layer is described. The barrier layer is deposited by sputter deposition under a nitrogen-containing sputtering atmosphere to form a nitrogen-containing chromium or chromium alloy barrier layer. The barrier layer is effective to inhibit migration of cobalt from the underlying magnetic recording layer, reducing corrosion of the medium and improving magnetic recording performance.

Abstract: An improvement in an apparatus having an external casing defining a processing chamber for deposition of a film on a substrate and an opening in the processing chamber through which a substrate is introduced for deposition is described. The improvement comprises an internal casing member moveably mounted within the processing chamber for movement between a first position which allows deposition onto the substrate to occur and a second position at which the casing is in sealing engagement with the opening to form an isolation chamber within the processing chamber and effective to isolate the substrate from processing chamber. The invention also includes a method for reducing cross-contamination between processing chambers in such an apparatus and a method for reducing particulate contamination to media prepared in such a deposition apparatus.

Abstract: An improvement in a magnetic recording medium having an underlayer and first and second magnetic recording layers is described. The improvement, effective to reduce media noise, includes deposition of an interlayer between the first and second magnetic recording layers. The interlayer is deposited to a thickness of between 5-50 .ANG. and is composed of an CoCr-based alloy having a defined saturation magnetization.

Abstract: An apparatus for measuring the height and diameter of laser-zone texture bumps on a rigid magnetic disk substrate is disclosed. The apparatus has a disk holder for supporting and rotating the substrate, and an optical beam-source assembly for directing a focused laser beam on the substrate, and for shifting the position of the beam's illumination spot on the substrate in a tracking (radial) direction. An optical detection assembly in the apparatus measures the deflection of the laser beam due to specular reflection of the beam by laser-zone texture bumps, as a function of time, in both scanning (circumferential) and tracking directions.

Abstract: An apparatus for polishing one or more planar substrates, such as magnetic disks, between rotating polishing plates is described. The apparatus is designed to optimize uniformity and flatness of the substrates by maintaining a substantially constant parallel and coaxial alignment between the rotating polishing plates.

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 medium having an underlayer and a magnetic layer is described. The improvement, effective to increase the coercivity of the medium, includes deposition of an interlayer between the underlayer and the magnetic recording layer. The interlayer is deposited to a thickness of between 10-60 .ANG. and is composed of an CoCr-based alloy having a defined saturation magnetization.

Abstract: An apparatus and method for laser texturing of magnetic recording media are described. The apparatus includes an optical assembly, containing first and second mirrors, which are rotated and optionally shifted during a texturing operation. This optical assembly directs a pulsed laser beam onto a series of focused spots on the surface of a magnetic disk, creating a desired pattern of texturing while maintaining a constant focus of the beam at the surface of the disk.

Abstract: An improvement in a magnetic recording medium having an underlayer and a magnetic recording layer is described. The improvement, effective to reduce media anisotropy, includes deposition of a prelayer on the substrate, prior to deposition of the underlayer. The prelayer is deposited to a thickness of between 10-60 .ANG. and is composed of an CoCr-based alloy having a defined saturation magnetization.

Abstract: A bilayer magnetic recording medium having first and second magnetic recording layers separated by a nonmagnetic isolation layer is disclosed. The medium is characterized by a high coercivity, low noise and an improved overwrite. In producing the medium, the second magnetic layer is deposited under sputtering conditions effective to produce a higher coercivity.

Abstract: An apparatus for laser texturing the inner annular region of a substrate is described. The apparatus includes a Bernoulli holder for supporting the disc at a fixed distance from a support face in the holder, and a laser beam for directing a pulsed laser beam on the substrate's inner annular region. Also included is an optical assembly for varying the position of such a spot on such inner annular surface region of the substrate.

Abstract: A texturing device for texturing a disc substrate of the type used in forming a thin-film medium is described. The device includes a rotatable assembly having a first pad attached to one end of a spindle and an annular ring having a second pad attached on one surface. Each pad defines a texturing surface for texturing the inner and outer regions of the disc substrate.

Abstract: A magnetic thin-film medium characterized by high coercivity, loop squareness, and signal-to-noise ratio characteristics. The medium includes a disc-like substrate, a sputtered Cr underlayer having a thickness between 100-300 .ANG., and a sputtered Co alloy magnetic thin-film layer having a thickness between 250-800 .ANG.. The sputtered Cr and magnetic layers are preferably formed under sputtering conditions in which a negative bias of between -50 to -600 volts is applied to the substrate.

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 target assembly for use in forming a protective overcoat in a magnetic recording medium is described. The assembly includes a centrally positioned target with inner and outer magnetic means adjacent the target. A sputtering shield is positioned between the target and the medium for controlling the amount and angle of material deposition on the medium. The assembly is effective to deposit an overcoat having a greater thickness in the inner landing zone of the medium than in the outer data zone. A method of using the assembly is also disclosed.

Abstract: A method for forming an overcoat having first and second layers in a magnetic recording medium is described. The first overcoat layer is deposited in a first sputtering chamber where the magnetic means for confining target plasma in the chamber are oriented to retain magnetic-field confinement about the target surface and to produce magnetic field lines between directly confronting portions of the confronting sputtering targets. The second overcoat layer is deposited under a nitrogen-containing atmosphere.