Abstract: A magnetic recording medium comprising a non-magnetic support, at least one primer layer formed on one surface of the non-magnetic support, a magnetic layer formed on the primer layer, and a backcoat layer formed on the other surface of the non-magnetic support, wherein the magnetic layer has a thickness of 0.30 ?m or less and a centerline average surface roughness Ra of 3.2 nm or less, and (P1?P0) is 30 nm or less and (P1-P20) is 5 nm or less in which P0 is an averaged height of projections of the magnetic layer, and P1, P2, - - - and P20 are heights of the highest, the second highest, - - - and the 20th highest projections of the magnetic layer, respectively.

Abstract: The present invention is a high-frequency current essentially of M—X—Y, where M is Fe, Co, and/or Ni, X is an element other than M or Y, and Y is F, N, and/or O. The maximum value ??max of the loss factor ?? of this material exists at 100 MHz to 10 GHz. A relative bandwidth bwr is not greater than 200% where the relative bandwidth bwr is obtained between two frequencies at which the value of ?? is 50% of ??max and normalizing the frequency bandwidth at the center frequency.

Abstract: A table pad coupling system including a first table pad and a second table pad. The first table pad having a plurality of peripheral surfaces including a first peripheral surface and a second peripheral surface, the first peripheral surface opposite the second peripheral surface. The first table pad additionally including a plurality of magnets positioned within the first table pad, the plurality of magnets including a first magnet associated with the first peripheral surface and a second magnet associated with the second peripheral surface, the first and second magnets having a surface of a same magnetic polarity, the surface of the first magnet and the surface of the second magnet outwardly oriented proximate the respective first and second peripheral surfaces.

Abstract: A perpendicular magnetic recording medium, comprises a substrate; a soft-magnetic layer formed on the substrate; an NaCl-type oxide layer for orientation control formed on the soft-magnetic layer, having a thickness of from more than 0 to less than 10 nm; and a magnetic recording layer formed on the NaCl-type oxide layer for orientation control, comprising a maghemite thin film. Such a perpendicular magnetic recording medium is capable of showing excellent magnetic properties, a high recording resolution and improved surface properties.

Abstract: A polyurethane having at least one anionic anchor group L, the anchor group L being covalently bonded to a polyether segment having at least one nitrogen atom in the polyurethane.

Abstract: A system for making at least one visual advertisement using at least one stepped surface, comprising: an array of decals displaying one or more visual advertisements on a stepped surface; a plurality of signage substrates wherein the decals are applied to the signage substrates, and; at least one guide mechanism adhered to the stepped surface, wherein each of the signage substrates is positioned by the guide mechanism.

Abstract: A magnetic-ring structure includes at least two states, and at least one twisted state that includes a 360° domain wall that can exist over a wide range of applied fields.

Abstract: A magnetic recording medium, and method of manufacturing the same, is provided with excellent recording performance by employing a granular magnetic layer having a specified composition. A magnetic recording medium according to the present invention comprises a nonmagnetic underlayer, a granular magnetic layer, a protective film, and a liquid lubrication layer sequentially laminated on a nonmagnetic substrate. The granular magnetic layer consists of ferromagnetic crystal grains containing cobalt and nonmagnetic grain boundary region surrounding the ferromagnetic crystal grains. The ferromagnetic crystal grains contain platinum in the range of 15 at % to 17 at %.

Abstract: The present invention provides a magnetic recording medium such as a flexible disk which is capable of high-density recording and is excellent in magnetic property. The magnetic recording medium comprises a magnetic layer, including a cobalt-containing ferromagnetic alloy and a non-magnetic material, on at least one surface of a non-magnetic substrate, wherein the ferromagnetic alloy forms a columnar structure.

Abstract: A perpendicular magnetic recording disk having a soft magnetic film disposed between a substrate and a magnetic recording layer. The soft magnetic film includes a soft magnetic underlayer and one or more layer groups having a spacer layer and a soft magnetic layer disposed above the spacer layer in each layer group. The spacer layers induce anti-ferromagnetic coupling between the surrounding ferromagnetic layers. The spacer layers may be comprised of ruthenium. The soft magnetic layers may have a granular decoupled structured through the use of a segregate.

Abstract: A data/information storage and retrieval medium, comprising: (a) a substrate including a surface; and (b) a thin layer or film of an in situ networked or cross-linked polymeric lubricant thin film bonded to the surface, the thin layer or film of polymeric lubricant obtained from a polymerizable perfluoropolyether derivative by supplying thermal or infra-red (IR) energy thereto.

Abstract: An inplane magnetic recording medium having high S/N and thermal stability and a reliable magnetic storage device having surface recording density of 50 megabit/mm2 or more is described. The magnetic recording medium includes magnetic layers formed on a nonmagnetic substrate with a plurality of ground layers therebetween, at least one of the ground layers formed from an alloy of a body-centered cubic structure containing Cr as a main component and B of from 2 atomic % to 12 atomic %. Main components of the magnetic layers include a lower magnetic layer containing Co and Cr of from 10 atomic % to 16 atomic %, with film thickness of from 1.5 nm to 4.5 nm, and an upper magnetic layer containing Co, coupling anti-ferromagnetically with the lower magnetic layer through nonmagnetic intermediate layers.

Abstract: The chemical conversion film containing, at least as the constituent components thereof, (a) at least one of the metals selected from molybdenum, zirconium, vanadium, and tungsten; (b) a rare earth metal constituting the magnet; and (c) oxygen, which is formed on the surface of a rare earth metal-based permanent magnet according to the present invention, contains a composite metal oxide provided on the surface of the R-rich phase having a lower oxidation-reduction potential through a preferential reaction of the metallic ions that are present in the form of complex ions or oxide ions, such as of molybdenum, contained in the treatment solution, with the rare earth metals that elute from the magnet. Thus formed composite metal oxide reduces the difference in corrosion potential as to realize a uniform surface potential, and effectively suppresses the corrosion based on potential difference.

Abstract: A large-capacity magnetic storage apparatus is disclosed, capable of performing ultra-high density magnetic recording of 50 gigabits or more per 1 square inch. In a perpendicular magnetic recording medium having a non-magnetic intermediate layer and a magnetic recording layer sequentially formed, the non-magnetic intermediate layer is composed of a layer having a face-centered cubic structure and containing a non-magnetic elements excluding Pt. Specifically, the intermediate layer mainly contains at least one selected from the group of elements constituted of Al, Cu, Rh, Pd, Ag, Ir and Au, and is composed of a film having a face-centered cubic (f. c. c.) structure. The magnetic recording layer contains at least Co, Cr and Pt, and is composed of a film having a hexagonal close-packed (h. c. p.) structure. More preferably, a non-magnetic h. c. p. intermediate layer is provided between the non-magnetic intermediate layer and the magnetic recording layer.

Abstract: A perpendicular magnetic recording medium comprises a hard magnetic recording layer, a soft magnetic layer, and a non-magnetic intermediate layer between the hard magnetic recording-layer and the soft magnetic layer, wherein the hard magnetic recording layer includes an hcp-structured layer and a Co-alloy layer which may be either a Co3Pt-alloy layer or an hcp CoPt-based alloy layer positioned adjacent to the hcp-structured layer. A magnetic disc drive storage system that includes the perpendicular magnetic recording medium is also included.

Abstract: A magnetic recording medium and a magnetic recording device using the same. The magnetic recording medium has a nonmagnetic substrate having applied thereon, through a crystal orientation-improving layer and a seed layer, a magnetic recording layer. The seed layer consists of a material having a higher surface energy than that of the crystal orientation-improving layer.

Abstract: A carbon nanotube which exhibits ferromagnetism without a ferromagnetic metal imparted thereto and also has high thermal stability is provided. The carbon nanotube is characterized by being doped with nitrogen (which differs from carbon in valence electron) such that the doped nitrogen is segregated in a strip form at one end of the carbon nanotube. The thus doped nitrogen causes the carbon nanotube to have a difference in electron density and to exhibit ferromagnetism. The present invention makes it possible to provide a carbon nanotube exhibiting ferromagnetism without the necessity of imparting any magnetic metal thereto.

Abstract: The chemical conversion film containing, at least as the constituent components thereof, (a) at least one of the metals selected from molybdenum, zirconium, vanadium, and tungsten; (b) a rare earth metal constituting the magnet; and (c) oxygen, which is formed on the surface of a rare earth metal-based permanent magnet according to the present invention, contains a composite metal oxide provided on the surface of the R-rich phase having a lower oxidation-reduction potential through a preferential reaction of the metallic ions that are present in the form of complex ions or oxide ions, such as of molybdenum, contained in the treatment solution, with the rare earth metals that elute from the magnet. Thus formed composite metal oxide reduces the difference in corrosion potential as to realize a uniform surface potential, and effectively suppresses the corrosion based on potential difference.

Abstract: A perpendicular magnetic recording medium including a substrate, a soft-magnetic backing layer formed on the substrate, a magnetic recording layer having perpendicular magnetic anisotropy formed on the backing layer, and a leakage magnetic field control layer having ferrimagnetism formed on the magnetic recording layer. The leakage magnetic field control layer is exchange-coupled to the magnetic recording layer antiferromagnetically or ferrimagnetically to thereby suppress the influence of leakage magnetic fields from the backing layer and the magnetic recording layer and reduce the medium noise.

Abstract: A magnetic recording medium comprising a flexible support, a first recording layer, an intermediate layer and a second recording layer in this order, wherein the second recording layer comprises a ferromagnetic metal alloy comprising Co, Pt and Cr, and a nonmagnetic oxide.

Abstract: The applicants disclose a thin film magnetic media structure with a pre-seed layer of CrTiAl. The CrTiAl pre-seed layer presents an amorphous or nanocrystalline structure. The CrTiAl pre-seed layer improves in-plane c-axis orientation while maintaining a good orientation ratio. The pulse transition width (PW50) is narrowed and the soft error rate is improved. The preferred seed layer is RuAl.

Abstract: A method for manufacturing single crystal ceramic powder is provided. The method includes a powder supply step for supplying powder consisting essentially of ceramic ingredients to a heat treatment area with a carrier gas, a heat treatment step for heating the powder supplied to the heat treatment area at temperatures required for single-crystallization of the powder to form a product, and a cooling step for cooling the product obtained in the heat treatment step to form single crystal ceramic powder. The method provides single crystal ceramic powder consisting of particles with a very small particle size and a sphericity being 0.9 or higher.

Abstract: A magnetic recording medium comprising a flexible support and a magnetic layer selected from a cobalt/palladium multilayer film and a cobalt/platinum multilayer film.

Abstract: Magnetic particles are prepared containing a magnetic core coated with a glass layer having a substantially pore-free class surface or having pores with a diameter offices than 10 nm. The particles are used for separating biological material such as nucleic acids. A preferred process of preparing the particles is by forming a mixture of magnetic cores with a sol formed from an alcohol and a metal alkoxide, spray-drying the mixture to coat the cores with a layer of gelled sol, and heating the coated cores to obtain the magnetic glass particles. Preferably, the particles have an average particle size of less than 100 ?m. The magnetic core may be a composite material containing a mica core and magnetite particles immobilized on the mica core, and the glass layer may contain boron oxide. Magnetic core materials include magnetite (Fe3O4) and Fe2O3.

Abstract: A magnetic recording medium based on the perpendicular recording system, which has high coercivity and low medium noise, is provided by using an underlayer which has a thin film thickness and which makes it possible to improve the orientation of a recording layer. The magnetic recording medium based on the perpendicular recording system has the recording layer which is formed of a CoPtCr alloy magnetic film containing oxygen. The magnetic recording medium has such a structure that an adhesive layer 2, a soft magnetic back layer 3, the underlayer 4, the recording layer 5, and a protective layer 6 are successively stacked on a substrate 1. A CoCrRu film, which has a film thickness of 5 nm to 20 nm, is used as the underlayer for the recording layer formed of the CoPtCr alloy magnetic film containing oxygen. Thus, it is possible to improve the crystalline orientation of the recording layer with the underlayer having the thin film thickness.

Abstract: A magnetic recording medium 100 comprises, on a substrate 1, a first orientation control layer 2, a second orientation control layer 4, a soft magnetic layer 6, a non-magnetic layer 8, a recording layer 12, and a carbon protective layer 14. The recording layer 12 is formed of an FePt ordered alloy phase which exhibits ferromagnetism and an FePt3 ordered alloy phase which exhibits paramagnetism. Accordingly, the magnetic coupling force, which acts between those of the FePt ordered alloy phase, is broken by the paramagnetic FePt3 ordered alloy phase. The magnetic interaction between those of the FePt ordered alloy phase is reduced, and thus the noise is reduced. Further, the high density recording can be performed, and the medium is excellent in thermal stability, because the FePt ordered alloy having high crystalline magnetic anisotropy is used for the recording layer 12.

Abstract: A magnetic recording medium comprises: a non-magnetic base film; and a magnetic recording layer comprising a binder resin and black magnetic acicular composite particles having an average particle diameter of 0.051 to 0.35 ?m, comprising magnetic acicular cobalt-coated iron oxide particles or magnetic acicular metal particles containing iron as a main component, a coating formed on surface of the magnetic acicular particles, comprising at least one organosilicon compound selected from the group consisting of: (1) organosilane compounds obtainable from alkoxysilane compounds, and (2) polysiloxanes or modified polysiloxanes, and a carbon black coat formed on the coating layer comprising said organosilicon compound, in an amount of from more than 10 to 40 parts by weight based on 100 parts by weight of said magnetic acicular particles.

Abstract: A master information carrier with excellent durability is provided, for the use of static and a real lump-sum recording of digital information signals on magnetic recording medium. The master information carrier comprises a non-magnetic substrate on which a ferromagnetic film is disposed with an embossed pattern. Protrusions of the embossed pattern correspond to a disposition of the digital information signals. Recessed portions of the embossed pattern of the ferromagnetic film are filled with non-magnetic solid material. Alternately, A non-magnetic substrate has an embossed pattern and recessed portions of the embossed pattern correspond to a disposition of the digital information signals. A ferromagnetic film is filled in the recessed portions of the embossed pattern.

Abstract: Disclosed are a double-layer perpendicular magnetic recording medium having a high medium S/N at a recording density of 50 Gbit or more per square inch and a magnetic storage apparatus with high reliability, which shows a low error rate. In the perpendicular magnetic recording medium in which a pre-coating layer, a soft magnetic underlayer, an intermediate layer, and a perpendicular recording layer are sequentially formed on a substrate, the soft magnetic underlayer contains Fe, Ta and C as main components, a Ta concentration is set to a range from 8 at % to 15 at % , and a ratio of a C concentration to the Ta concentration (C concentration/Ta concentration) is set to a range from 0.5 to 0.9.

Abstract: A thin film magnetic media structure with a bi-layer structure of amorphous chromium titanium (CrTi) followed by an amorphous layer of nickel phosphorus (NiP) is disclosed. After the NiP has been deposited it is exposed to oxygen to form an oxidized surface. Preferably the underlayer is deposited directly onto the oxidized NiP surface. The bi-layer structure of CrTi/NiP promotes excellent in-plane crystallographic orientation in the cobalt alloy magnetic layer(s) and allows an ultra-thin chromium underlayer to be used which provides better control over grain size and distribution. When the CrTi/NiP bi-layer structure is combined with a circumferentially textured substrate, preferably glass, a high Mrt orientation ratio (OR) results.

Abstract: Oriented longitudinal magnetic recording media on direct texture glass or glass-ceramic substrate with a film structure of one or more Ni-containing layer, a Cr-containing underlayer, a Co-containing magnetic layer and carbon overcoat exhibits are capable of achieving Mrt OR of >1.5, preferably >1.85. Such highly oriented glass media shows a significant SNR (>2 dB) and parametric improvement over the counterpart isotropic media with the same film structure on non-textured glass or glass-ceramic substrates.

Abstract: A magnetic recording medium includes data signal storage regions each having first magnetic substance cells, and tracking servo signal storage regions each having second magnetic substance cells. The first magnetic substance cells are separated from one another by nonmagnetic substance and the second magnetic substance cells are separated from one another by nonmagnetic substance, and the first magnetic substance cells and the second magnetic substance cells have different magnetic properties.

Abstract: A magnetic recording media formed of magnetic alloy layer of Co as the main component on a substrate through an under-layer, a protective layer and a lubricant layer, stacked in this order, said under-layer comprises plural under-layers including a first under layer of a substantially amorphous and a second under layer of crystalline stacked in this order; and a ? BH[0.01, 50] defined by |BH[0.01%]?BH[50%]|, as the difference between a height BH[0.01%] where a Bearing ratio is 0.01% and a height BH[50%] where a Bearing ratio is 50%, is not less than 3 nm and not more than 6 nm, where a Bearing Curve is given by a surface roughness curve of magnetic recording media.

Abstract: A thin film magnetic media structure with a pre-seed layer of CrTi is disclosed. The CrTi pre-seed layer presents an amorphous or nanocrystalline structure. The preferred seed layer is RuAl for use with the CrTi pre-seed layer. The use of the CrTi/RuAl bilayer structure provides superior adhesion to the substrate and resistance to scratching, as well as, excellent coercivity and signal-to-noise ratio (SNR) and reduced cost over the prior art. One embodiment of the invention sputter-deposits a CrTi pre-seed layer and a RuAl seed layer followed by at least one underlayer and at least one magnetic layer on a circumferentially polished substrate structure to achieve an Mrt orientation ratio greater than one. Two methods according to the invention allow the Mrt orientation ratio of the disk to be adjusted or maximized by varying the thickness of the RuAl seed layer and/or altering the atomic percentage of titanium in the pre-seed layer.

Abstract: Ink compositions with modified properties result from using a powder size below 100 nanometers. Colored inks are illustrated. Nanoscale coated, uncoated, whisker inorganic fillers are included. The pigment nanopowders taught comprise one or more elements from the group actinium, aluminum, antimony, arsenic, barium, beryllium, bismuth, cadmuim, calcium, cerium, cesium, chalcogenide, cobalt, copper, dysprosium, erbium, europium, gadolinium, gallium, gold, hafnium, hydrogen, indium, iridium, iron, lanthanum, lithium, magnesium, manganese, mendelevium, mercury, molybdenum, neodymium, neptunium, nickel, niobium, nitrogen, oxygen, osmium, palladium, platinum, potassium, praseodymium, promethium, protactinium, rhenium, rubidium, scandium, silver, sodium, strontium, tantalum, terbium, thallium, thorium, tin, titanium, tungsten, vanadium, ytterbium, yttrium, zinc, and zirconium.

Abstract: A magnetic recording medium containing a niobium-containing seedlayer having a thickness from about 1 ? to about 40 ?, and a method of making the same. The seedlayer provides a recording media with relatively high remanent coercivity and relatively high signal to medium noise ratio.

Abstract: Magnetic films having magnetic regions and non-magnetic regions are disclosed. The film is subjected to ion irradiation in order to produce chemically disordered regions in the film. The irradiated disordered regions may correspond to the non-magnetic regions of the film. Alternatively, the irradiated disordered regions may correspond to the magnetic regions of the film. In one embodiment, portions of a magnetic CrPt3 film are converted to non-magnetic regions by irradiating the regions with boron ions which disorder the CrPt3 film in the treated regions. The film may be patterned into magnetic regions and non-magnetic regions for applications such as magnetic recording media in computer disc drive systems.

Abstract: A decorative material is disclosed which comprises two polarizers and at least one phase-shifting plate placed between the polarizers. Each polarizer has a controlled direction of polarization axis. The phase-shifting plate represents a continuous layer of an optically anisotropic material containing regions differing by optical properties.

Abstract: A magnetic recording medium comprises a magnetic recording layer 63 which is formed by using an ordered alloy containing B on a substrate 1 containing an amorphous component. A part of B in the ordered alloy is segregated in a grain boundary, and thus the magnetic interaction, which acts between magnetic grains, can be reduced. Accordingly, it is possible to form fine and minute magnetic domains in the magnetic recording layer 63, and it is possible to reduce the medium noise as well. The temperature, at which the substrate is heated during the film formation of the magnetic recording layer 63, can be suppressed to be low, because the ordering temperature for the ordered alloy containing B is lower than those of ordered alloys not containing B. Therefore, it is possible to use a substrate made of glass which is suitable for the mass production. The magnetic recording layer 63 is also excellent in thermal stability because of the use of the ordered alloy having high magnetic anisotropy.

Abstract: A magnetic thin film disk for use in a disk drive with a ruthenium-aluminum (RuAl) seed layer with B2 structure followed by a NiAl layer is described. The disk has reduced noise and increased squareness which results in improved recording performance in a disk drive utilizing the disk. The improved disk is formed by first depositing the RuAl seed layer on the substrate then the NiAl layer is deposited onto the NiAl, followed by the other layers required for a magnetic disk such as an underlayer material with a lattice parameter compatible with RuAl such as Cr-alloy, followed by a standard hcp magnetic material. The RuAl seed layer promotes a [100] preferred orientation in the underlayer which in turn promotes a [11{overscore (2)}0] preferred orientation in the magnetic layer.

Abstract: A magnetic recording medium 100 comprises, on a substrate 1, a soft magnetic layer 3, a seed layer 5, and a recording layer 6 having an artificial lattice structure. The seed layer 5 is formed of Pd and one selected from the group consisting of Si, B, C, and Zr. Accordingly, the magnetic exchange coupling force of the recording layer 6 in the in-plane direction can be weakened. Minute recording magnetic domains can be formed in the recording layer 6, and the magnetization transition area is distinct as well. Thus, the medium noise is reduced. That is, reproduction can be performed with a low medium noise even when information is recorded at a high density. A magnetic storage apparatus, which is provided with the magnetic recording medium as described above, can achieve an areal recording density of 150 Gigabits/square inch.

Abstract: A ferromagnetic iron alloy powder for a magnetic recording medium is composed of acicular iron-base particles of an average major axis length (X) of not less than 20 nm and not greater than 80 nm and have oxygen content of not less than 15 wt % and coercive force (Hc) of not less than [0.0036 X3?1.1 X2+110 X?1390 (Oe)] (where X is average major axis length expressed in nm). The ferromagnetic iron alloy powder is obtained by reacting metal powder composed of acicular iron-base particles having an average major axis length of not less than 20 nm and not greater than 80 nm with pure water in substantial absence of oxygen to form a metal oxide film on the particle surfaces. Optionally, the particles can be reacted with a weak oxidizing gas by a wet or dry method.

Abstract: A system and method for forming servo patterns on magnetic media is disclosed. A magnetic film coated with a layer of polystyrene is stamped with a nickel stamper reproducing the negative image of the stamped pattern on the polystyrene. Ions are then accelerated towards the surface of the polystyrene, which stopps the ions in the areas where the polystyrene is thick and allows the ions to penetrate through to the magnetic layer in the areas where the polystyrene is thin. The ions, which penetrate through to the magnetic layer, interact with the magnetic layer altering the magnetic layer's structure reducing its coercivity (Hc) and remnant moment (Mrt). This reproduces the stamped polystyrene pattern on the magnetic layer. The polystyrene is then removed by oxygen plasma etching the surface leaving behind a patterned magnetic media.

Abstract: The present invention provides a surface-treated substrate for a magnetic recording medium, and a magnetic recording medium comprising a recording layer, wherein the surface-treated substrate can contain thick film which has adhesion strong enough to withstand leveling process such as polishing in the formation of film on the Si substrate. More specifically, the present invention provides a surface-treated substrate for a magnetic recording medium, comprising a Si substrate and a primer plating layer on the Si substrate, wherein the primer plating layer is film which comprises a metal and a Si oxide. Furthermore, the present invention provides a surface-treated substrate for a magnetic recording medium, comprising a Si substrate and a primer plating layer on the Si substrate, wherein at least 5 and at most 50 protrusions of a height of at least 100 nm per 100 &mgr;m2 are present on a surface of the primer plating layer.

Abstract: A magnetic recording disk has a ferromagnetic structure of two ferromagnetic layers antiferromagnetically coupled together with an improved antiferromagnetically coupling (AFC) film. The AFC film is an alloy of Ru100-xFex where x is between approximately 10 and 60 atomic percent. This AFC film increases the exchange coupling by up to a factor or two and has an hcp crystalline structure making it compatible with Co alloy ferromagnetic layers.

Abstract: The applicants disclose a thin film magnetic media structure with a pre-seed layer of CrTiAl. The CrTiAl pre-seed layer presents an amorphous or nanocrystalline structure. The CrTiAl pre-seed layer improves in-plane c-axis orientation while maintaining a good orientation ratio. The pulse transition width (PW50) is narrowed and the soft error rate is improved. The preferred seed layer is RuAl.

Abstract: Perpendicular magnetic media are described for use in magnetic recording and data storage. Seed layer compositions are described which can facilitate perpendicular magnetic anisotropy in subsequently deposited magnetic layers. In particular, nickel-iron-chromium (NiFeCr) alloys or nickle-chromium (NiCr) alloys can be used as seed layers which cause a subsequently multi-layered magnetic stack to assume perpendicular magnetic anisotropy. In this manner, high perpendicular magnetic anisotropy can be achieved and storage densities of media may be increased.

Abstract: A dual-layer type perpendicular magnetic recording disk for use in a perpendicular magnetic recording system that uses a single pole recording head has a laminated underlayer that has at least two ferromagnetic films exchange-coupled across an antiferromagnetic coupling layer. The magnetic moments of the ferromagnetic layers in the laminated underlayer are oriented antiparallel. The laminated underlayer provides a soft magnetically permeable flux return path without undesirable domain walls and associated media noise, with controllable permeability and minimization of saturation of the upper ferromagnetic layers. In one embodiment the moments of the ferromagnetic layers in the underlayer are oriented generally radially on the disk. In another embodiment the moments are oriented generally circumferentially in the track direction on the disk, so that the beneficial effect of the soft magnetic underlayer occurs primarily only during the writing process.

Abstract: A magnetic recording medium for data storage uses a magnetic recording layer having at least two ferromagnetic films exchange coupled together antiferromagnetically across a nonferromagnetic spacer film. In this antiferromagnetically-coupled (AFC) recording layer the magnetic moments of the two ferromagnetic films are oriented antiparallel, and thus the net remanent magnetization-thickness product (Mrt) of the AFC recording layer is the difference in the Mrt values of the two ferromagnetic films. This reduction in Mrt is accomplished without a reduction in thermal stability of the recording medium. The lower ferromagnetic film in the AFC recording layer is a ferromagnetic CoCrFe alloy that does not require a nucleation layer between it and the Cr alloy underlayer. The medium with the CoCrFe alloy as the first or lower ferromagnetic film in the AFC recording layer has reduced intrinsic media noise.

Abstract: The invention refers to a new process for preparing coated crystals by coating crystal template particles with alternating layers of oppositely charged polyelectrolytes and/or nanoparticles.