Abstract: A novel colloidal silica slurry including additives for enhancing the removal rate of a metallic workpiece, preventing etch pits, and enhancing smoothness. These additives include HNO.sub.3, H.sub.2 O.sub.2 and Al(NO.sub.3).sub.3. In lieu of colloidal silica, colloidal alumina can be used. The metallic workpiece can be NiP, Ni, Al or other appropriate materials.

Abstract: A method of manufacturing a magnetic disk comprises the steps of: a) providing a substrate with a layer of an amorphous multi-component material at its surface; b) irradiating the amorphous layer (e.g. by applying heat from a heating element, laser beam, or the like) to thereby create micro-structurally changed regions in the amorphous layer; and c) chemo-mechanically polishing the amorphous layer to produce micro-texture features at or near the micro-structurally changed regions. The disk is then completed by depositing additional layers such as an underlayer, a magnetic layer, a protective overcoat, etc.

Abstract: A method for manufacturing a magnetic disk comprises the steps of depositing NiP (20) on a substrate (22); depositing NiNb (24) on the NiP; and laser texturing the NiNb. "Sombrero" shaped texture features are more easily formed on the substrate/NiP/NiNb structure than a substrate/NiP structure. The disk is completed by depositing an underlayer (e.g. sputtered Cr or NiP), a magnetic layer (e.g. a Co alloy) and a protective overcoat (e.g. by hydrogenated carbon).

Abstract: A method for texturing a glass ceramic substrate comprising the steps of applying a laser pulse to the substrate such that a portion of said substrate is heated to a temperature higher than the glass transition temperature of the glass phase of said substrate but lower than the melting point of the crystal phase of said substrate.

Abstract: A Co--Pt based magnetic alloy which has been doped with a relatively high amount of nitrogen, e.g., at or above 1 at. % is obtained having high coercivity, for example in the range of 1400 Oe or above, and an increased signal-to-noise ratio as compared to the same Co--Pt based alloy which has not been doped with nitrogen. The alloy is vacuum deposited, for example, by sputtering, and the nitrogen may be introduced from the sputtering gas or from the sputtering target. Other low-solubility elements providing the grain uniformity and isolation include: B, P, S, C, Si, As, Se and Te.

Abstract: A magnetic recording medium is provided with a structured nucleation layer. The structured nucleation layer comprises a fine-grained seed layer and an intermediate layer. The seed layer (e.g., NiAl, Ti, Cr--Cu, etc.) serves as a template for fine grained-growth of the intermediate layer. The intermediate (e.g., Cr, etc.) layer has preferred crystal textures and an appropriate lattice match to a subsequently deposited magnetic recording layer to allow epitaxial growth of the magnetic recording layer. The intermediate layer provides morphology and orientation to the magnetic recording layer. The magnetic recording layer (e.g., Co-alloy) includes a material which segregates to the alloy grain boundaries to isolate the grains thereof. Each grain of the magnetic recording layer is predominantly a single crystal of small size and uniformly spaced from adjacent grains. The easy axis of the magnetic recording material is predominantly in the plane of the disk, with a random in-plane orientation.

Abstract: A Co--Pt based magnetic alloy which has been sputtered with an oxide or nitride of a primary constituent of the magnetic layer, e.g., CoO below about 10 at. %, provides improved coercivity, squareness, and reduced noise as compared to magnetic alloys with oxygen introduced by other methods. The alloy is vacuum deposited, for example, by sputtering, and the oxide or nitride may be introduced from the sputtering target from which the magnetic layer materials come or from a separate sputtering target. Examples of such oxides and nitrides include CoO, Co.sub.2 O.sub.3, Co.sub.3 O.sub.4, CrO.sub.2, Cr.sub.2 O.sub.3, TiO.sub.2, Ta.sub.2 O.sub.5, Al.sub.2 O.sub.3, WO, CoN, Co.sub.2 N, TiN, TaN, CrN, NiN, etc.

Abstract: Definition of the required geometry of the air bearing surface ("ABS") of a magnetic head slider is achieved while providing an ABS which exhibits low wear, low friction, and low stiction at its interface with a disk surface, by securely embedding monocrystalline diamond particles into a lapping plate, removing substantially all particles from the plate which are not firmly affixed thereto, and lapping the slider in a linear, X-Y direction at a relatively high lapping pressure. Material susceptible to being dislodged during CSS is removed during the lapping process. Thus, the incidence of material dislodging from the ABS and increasing wear-induced stiction is substantially reduced, resulting in improved CSS performance. A desired microtexture is also applied to the ABS. Reduced pole tip recession is also observed.

Abstract: A hard disk drive utilizing a combination of thin film recording heads and media allows high density recording through virtual contact recording, while still providing excellent contact start stop performance and low stiction. The air bearing surface of the head has a microscopically fine texture which provides reliable mechanical performance with a constant and very low flying height. A skew insensitive constant flying height over the disk surface can be provided with the use of transverse pressure contour or cross-cut slider designs. The slider air bearing surface is textured by selective mechanical removal of subsurface damaged regions left behind during the diamond lapping of the slider air bearing surface, thereby leaving the slider less abrasive to the disk. A slider with this fine texture on the air bearing surface permits the use of a much smoother texture and thinner overcoat on the disk than currently possible using conventional sliders.

Abstract: Media according to the present invention is comprised of individual magnetic grains as small as 300 .ANG. or smaller in diameter, which are uniformly spaced apart by a distance between 5 and 50 .ANG. by a solid segregant. This media will typically exhibit coercivity and remanent coercivity squareness of at least 0.8 each, a switching field distribution of less than 0.2, and a coercivity of at least 1500 Oe (with a minimum required Pt content), while simultaneously providing the lowest media jitter noise for optimum magnetic performance. The media is deposited at a low partial pressure of water and in the presence of an optimum amount of contributant gas on a doped nucleation layer for grain growth control.

Abstract: An optimal structure for a quadrilayer magneto-optic data storage medium is described. The structure has superior characteristics of signal to noise, reflectivity, ellipticity, write sensitivity, and stability.

Abstract: A clamp for a memory disk having a disk aperture bounded by a cylindrical peripheral edge and chamfered peripheral edges includes facing clamp members having chamfered peripheral edges which are parallel to the chamfered edges of the disk aperture. The clamp directs forces to the disk chamfered edges substantially perpendicular to the disk sides thus preventing deformation or cracking of a clamped disk. Preferably, the disk is held between a chamfer on a housing and a chamfer on an expandable collet extending from the housing. A longitudinal movable expander extending through the housing and collet is attached to a pull bar to expand curved segments of the collet to first move the segments particularly the chamfer to a radial position opposite but spaced from a disk chamfered edge, then longitudinally to contact and clamp the disk with a predetermined force.

Abstract: A carrier plate (15) has essentially circular openings (11) for receipt of smaller diameter circular magnetic memory disks (20). Each disk has a plugged aperture, a planar annular band (23) on each side for receiving magnetic media (8), an outer peripheral edge (24) and a chamfer (22) therebetween. An integral stump segment (30) and a pair of integral U-shape channel retainers (40) extend from plate opening (11) to a position overlapping disk chamfer (22) to prevent a disk resting vertically on the stump segment (30) from falling out of the plate (15). Vertical holding walls (40) extend integrally and downwardly from a rear leg of the channel to insure vertical orientation of the disk (20) and stop walls (50) extend integrally and upwardly from that rear leg to prevent overtilting of the disk during its insertion into the plate (15). Gaps (31, 32, 33) are provided between the disk peripheral edge (24) and the opening (11) over about 248.degree.

Abstract: A magnetic thin film alloy comprising cobalt, chromium, nickel and platinum for horizontal recording has a high coercivity, good corrosion resistance, and good noise performance. The platinum has a concentration between 8 to 15 atomic percent, the chromium has a concentration of 3 to 8%, the nickel concentration is 5 to 10% and the balance consist of essentially cobalt. The magnetic alloy has a thickness less than 100 nm and is sputtered on an undercoat consisting of nickel and phosphorus. The phosphorus content is between 5 to 30 weight percent, and the nickel phosphorus has a thickness between 5 and 100 nm. Alternatively, other amorphous metallic thin film undercoats can be applied. By judicious selection of the amount of chromium and nickel in the alloy, the saturation magnetization can be kept high while still maintaining good corrosion resistance. In addition, the sputtered media exhibits low noise.

Abstract: A method for manufacturing a disk includes the step of forming a first nickel-phosphorus alloy layer on an aluminum substrate, e.g., by electroless plating. A second nickel-phosphorus layer is then sputtered onto the first nickel-phosphorus layer, and a magnetic alloy is sputtered onto the second nickel-phosphorus layer. The magnetic alloy is typically sputtered immediately after the second nickel-phosphorus layer is formed without removing the disk from the sputtering apparatus between the time the second nickel-phosphorus layer is formed and the time the magnetic alloy is formed. Because of this, contaminants are not capable of lodging on or affecting the surface of the disk prior to formation of the magnetic alloy. The second nickel-phosphorus layer is typically amorphous and therefore masks any nonuniformities in the surface of the first nickel-phosphorus layer.

Abstract: A glass disk is subjected to a chemical or gentle mechanical polishing step to remove microcracks or scratches in the disk surface prior to chemically texturing the disk. Thereafter, magnetic media is deposited onto the glass disk. We have discovered that by performing this pre-texturing polishing step, we can avoid the phenomenon of "linkage bumps," which could otherwise cause the resulting magnetic disk to fail a glide-type test or to cause a read/write head crash.

Abstract: A carbon film for protecting a magnetic disk is sputtered in the presence of hydrogen. If a sufficient amount of hydrogen is present in the sputtering chamber, the resulting carbon film will exhibit superior mechanical characteristics, i.e. an enhanced wear resistance during a contact-start-stop or drag test in a disk drive. Sputtering in the presence of hydrogen can be accomplished by either DC or RF magnetron sputtering, or DC or RF diode sputtering.

Abstract: A film of magnetic recording media is formed by sputtering an alloy of cobalt and platinum onto a substrate. The sputtering takes place in a chamber containing argon and nitrogen. The magnetic coercivity of the resulting film is controlled by varying the concentration of nitrogen in the sputtering chamber. By using this technique, the film coercivity is controlled without varying other important parameters such as the saturation magnetization. The film coercivity can also be controlled by varying the concentration of oxygen in the sputtering chamber.

Abstract: A film of magnetic recording media is covered with a layer comprising ZrO.sub.2. Advantageously, the ZrO.sub.2 layer inhibits corrosion in the underlying magnetic recording media. The ZrO.sub.2 layer also exhibits desirable mechanical properties, e.g. reduced stiction. In one embodiment of our invention, the ZrO.sub.2 is sputtered onto the magnetic recording media.

Abstract: A film of magnetic recording media is covered with a layer comprising ZrO.sub.2. Advantageously, the ZrO.sub.2 layer inhibits corrosion in the underlying magnetic recording media. The ZrO.sub.2 layer is wear resistant and also exhibits reduced static friction. In one embodiment of our invention, an intermediate layer is sputtered onto the media and the ZrO.sub.2 is sputtered onto the intermediate layer. Advantageously, the intermediate layer adheres strongly to both the media and the ZrO.sub.2. We have discovered that by providing the intermediate layer, static and dynamic friction between a read-write head and the disk tends to remain consistently low, and reliability of the disk is enhanced.