Abstract: The true roughness of highly granular perpendicular media is measured by forming an inverse replica of the surface of the media. The invention enables AFM measurements of granular media valley depth to more consistently predict the corrosion performance of the media. A liquid resist is used to first replicate the media topography and form the inverse replica. The narrow valleys in the original media are precisely modeled as sharp peaks on the replica. The height of the peaks are readily measured with an AFM tip. The resulting image is a negative of the original surface.

Abstract: A method for improving magnetic grain segregation in perpendicular recording media includes providing a substrate comprising a rigid support structure, depositing a soft underlayer on top of the substrate depositing an intermediate layer on top of the soft underlayer, providing a plurality of prospective segregants, determining the surface energies and the heat of formation of the prospective segregants and selecting the prospective segregant with a low surface energy and a high heat of formation. The method also includes providing at least one layer with surface energies progressively increasing to minimize the difference between the surface energy of a carbon overcoat and the segregant.

Abstract: An apparatus, system, and method are disclosed for guided growth of patterned media using monodisperse nanospheres. The apparatus includes nanoscale features extending from a substrate. The nanoscale features may be formed using electron-beam lithography and have a non-uniform cap. A spherical cap is formed on the non-uniform cap by hydrolysis and precipitation of monodisperse nanospheres on an immobilized nucleation site, the immobilized nucleation site attached with one end of the nanoscale feature. The system includes the apparatus and further includes monodisperse nanospheres formed of silicon dioxide spheres.

Abstract: Systems and methods are provided for burnishing a recording head in-situ in a magnetic recording disk drive. The burnishing process generates a tribocurrent, which is electricity generated by the rubbing of dissimilar materials. Different materials exhibit widely different tribocurrent characteristics while in sliding contact. The tribocurrent thus acts as an indicator of the particular materials of the recording head making contact with the magnetic recording media during different stages of the burnishing process. The tribocurrent is thus monitored to determine when it reaches a threshold value. The threshold value indicates that the burnishing has exposed a particular material of the recording head. Thus, the burnishing process may be stopped upon the tribocurrent reaching the threshold value so that the read sensor of the recording head is not burnished and inadvertently damaged.

Abstract: Lubricant with non-terminal functional groups. The location of the functional groups minimizes free chain length and molecular weight of a lubricant while simultaneously maximizing evaporation temperature. The locations of the functional groups to the backbone of the molecule of the lubricant allows for shorter lengths of free backbone length between functional groups attached to a lubricated surface. The lubricant lubricates mechanical devices including hard disk drives. The lubricant can also be added to media or other mechanical parts in conjunction with other lubricants.

Abstract: Methods of performing nanoimprint lithography are described. For one method, a master tool and a stamper tool are formed to provide nanometer-scale imprinting. A release layer comprised of a perfluoropolyether diacrylate material is formed on the master tool and the stamper tool. The master tool and the stamper tool are used to form patterns in resist material, such as hole or pillar patterns. The resist material as described herein has lower viscosity and lower surface tension than prior resist materials allowing for more uniform replication of the patterns.

Abstract: The present invention provides a novel method for reducing pad burnish damages on magnetic recording media. The method of the present invention reduces burnish damage and increases glide yield without compromising disk flyability, durability and general quality.

Abstract: Lubricant with non-terminal functional groups. The location of the functional groups minimizes free chain length and molecular weight of a lubricant while simultaneously maximizing evaporation temperature. The locations of the functional groups to the backbone of the molecule of the lubricant allows for shorter lengths of free backbone length between functional groups attached to a lubricated surface. The lubricant lubricates mechanical devices including hard disk drives.

Abstract: A disk drive having a layer of lubricant on a disk surface, where an undesirable lubricant layer thickness modulation is reduced by varying ?/f during operation of the disk drive. Here ? is the angular velocity of the disk and f is a resonant frequency of a head assembly containing the head. In this manner, the amplitude of the lubricant thickness modulation is decreased, improving disk drive performance. The ratio ?/f is preferably varied by varying the disk angular velocity ?.

Abstract: A method is presented for measuring the height of an air-bearing separating a flying component from a rotating surface using physical deformation of a small amount of material deposited on the surface. One embodiment of the invention is a method of measuring the fly-height of a slider using physical deformation of material deposited on the disk. Small amounts of the deformable material such as a viscoelastic lubricant are placed on a limited area of the disk so that the slider can otherwise fly normally. The slider's fly-height is established over the unaltered portion of the disk, then the slider impacts the deformable material. This process results in the deformable material being flattened or removed above the fly-height of the slider. The height of the remaining material is then measurable as the fly-height.

Abstract: A disk drive having a layer of lubricant on a disk surface, where an undesirable lubricant layer thickness modulation is reduced by varying ?/f during operation of the disk drive. Here ? is the angular velocity of the disk and f is a resonant frequency of a head assembly containing the head. In this manner, the amplitude of the lubricant thickness modulation is decreased, improving disk drive performance. The ratio ?/f is preferably varied by varying the disk angular velocity ?.

Abstract: A method is presented for measuring the height of an air-bearing separating a flying component from a rotating surface using physical deformation of a small amount of material deposited on the surface. One embodiment of the invention is a method of measuring the fly-height of a slider using physical deformation of material deposited on the disk. Small amounts of the deformable material such as a viscoelastic lubricant are placed on a limited area of the disk so that the slider can otherwise fly normally. The slider's fly-height is established over the unaltered portion of the disk, then the slider impacts the deformable material. This process results in the deformable material being flattened or removed above the fly-height of the slider. The height of the remaining material is then measurable as the fly-height.

Abstract: A magnetic data recording medium substrate has a contact zone and a data zone. The contact zone is textured by forming multiple texturing features, each having a bell-shaped profile resembling a Gaussian curve. The features preferably are formed by pulsed laser energy applied to a glass substrate, or to an aluminum nickel-phosphorous substrate coated with a glass layer. As compared to previous laser texturing approaches, the laser beam is less narrowly focused to provide a beam impingement area with a diameter of at least three microns, forming texturing features with diameters of at least three microns. The texturing features preferably are uniform in height and diameter, and may be symmetrical or have asymmetrical aspects, so long as bell-shaped profiles are present in the direction of travel of the recording medium, relative to transducing heads.

Abstract: A overcoat layer of TiSixNy for use on a magnetic thin film disk is disclosed. The overcoat of the invention has high hardness, provides corrosion protection and has low surface energy which reduces contaminant attraction. The TiSixNy film is conductive and, therefore, reduces the deleterious effects of tribocharging.

Abstract: A magnetic data storage medium includes a dedicated transducing head contact zone for engaging an air bearing slider, primarily when the disk is stationary. The contact zone is textured with an irregular sequence of spaced apart nodules forming a substantially circumferential, spiral path. The spiral path includes multiple terms that define a uniform radial pitch. The circumferential pitch is irregular, more preferably determined according to pseudo-random function in which the actual spacing intervals vary about a nominal interval, over a range comparable to, but generally less than, the interval. The pseudo-random array can be formed by a texturing process that includes directing a focused laser beam onto the contact zone. The disk is rotated to maintain a constant circumferential speed relative to the laser, and also is translated radially to provide the desired radial pitch.

Abstract: A quantitative stiction model for HDI has been proposed, which takes into account local redistribution of lubricant and its effect on meniscus formation. Equations for calculating stiction have been obtained for three distinct situations, depending on the ratio of the interface separation to the lubricant film thickness and the interactions among contacting asperities. The model has been applied to HDIs consisting of either regular or random texture. The model predicts that the relationship between stiction and the real area of contact is not necessarily monotonic. Instead, stiction exhibits a broad minimum for intermediate values of true contact. This prediction is consistent with some of the experimental results reported in the literature. The model also suggests that the role of various roughness parameters on stiction are not independent of one another.

Abstract: Lubricated magnetic recording discs are provided by vapor deposition of narrow molecular weight fractions of a terminally functionalized perfluoropolyether. The coatings are found to provide stable lubrication over extended periods of time in CSS cycles.

Abstract: A process for selective liquid-liquid extraction of germanium from an aqueous acidic liquor containing, besides germanium, at least one other metal selected from the group which comprises cadmium, zinc, cobalt, iron, arsenic and nickel. This process includes extracting germanium from said aqueous liquor by contacting said liquor with an organic medium containing a diluent and an extractant, said diluent being immiscible with said aqueous liquor. The major part of germanium passes from said aqueous liquor to an organic phase which is subsequently submitted to a stripping step by contacting with an alkaline medium, with formation of an aqueous phase containing the major part of germanium from said aqueous liquor.

Abstract: A process for selective liquid-liquid extraction of germanium from an aqueous acidic liquor containing, besides germanium, at least another metal selected from the group which comprises cadmium, zinc, cobalt and nickel. This process includes extracting germanium from said aqueous liquor by contacting said liquor with an organic medium containing a diluent and an extractant, said diluent being immiscible with said aqueous liquor. The major part of germanium passes from said aqueous liquor to an organic phase which is subsequently submitted to a stripping step by contacting with an alkaline medium, with formation of an aqueous phase containing the major part of germanium from said aqueous liquor.