Abstract: Provided are a method for production of a hard disk substrate capable of obtaining a smooth surface of a plating film by electroless NiP plating that is not degraded in corrosion resistance against the acid solution and such a hard disk substrate.

Abstract: Provided are a method for production of a hard disk substrate capable of obtaining a smooth surface of a plating film by electroless NiP plating that is not degraded in, but exhibits corrosion resistance against, an acid solution and such a hard disk substrate.

Abstract: A method of manufacturing a perpendicular magnetic recording medium substrate is capable of reducing the waviness of all wavelength components and a recording medium is capable of reducing contact with a magnetic head to improve the flying stability of the magnetic head. The method includes two polishing operations. The first operation includes polishing a substrate having a Ni—P-based alloy underlayer with a first porous material that includes 0.1 wt % to 25 wt % of alumina, titania, silica, and zirconia abrasive while supplying a first slurry liquid including an organic or inorganic acid and a first abrasive to the underlayer of the substrate. The second operation includes polishing a surface of the underlayer polished in the first polishing with a second porous material while supplying a second slurry liquid including an organic or inorganic acid and a second abrasive with a grain diameter smaller than that of the first abrasive.

Abstract: A main object of the present invention is to provide a suspension substrate capable of supplying electric power easily to an assisting element fitted thereto. The object is attained by providing a suspension substrate comprising a metal supporting substrate, an insulating layer formed on the metal supporting substrate, and a wiring layer formed on the insulating layer, wherein the metal supporting substrate has, in a recording element mounting region for mounting a recording element, an opening for arranging and fitting thereinto a heat assisting element, wherein the wiring layer has a heat assisting wiring layer having a terminal section for supplying electric power directly to the heat assisting element.

Abstract: A nanocomposite article that includes a single-crystal or single-crystal-like substrate and heteroepitaxial, phase-separated layer supported by a surface of the substrate and a method of making the same are described. The heteroepitaxial layer can include a continuous, non-magnetic, crystalline, matrix phase, and an ordered, magnetic magnetic phase disposed within the matrix phase. The ordered magnetic phase can include a plurality of self-assembled crystalline nanostructures of a magnetic material. The phase-separated layer and the single crystal substrate can be separated by a buffer layer. An electronic storage device that includes a read-write head and a nanocomposite article with a data storage density of 0.75 Tb/in2 is also described.

Abstract: A thermally-assisted magnetic recording (TAMR) medium of the present invention includes: a magnetization direction arrangement layer on a substrate; and a magnetic recording layer on the magnetization direction arrangement layer, wherein the magnetization direction arrangement layer is made of at least one selected from a group consisting of Co, Zr, CoZr, CoTaZr, CoFeTaZrCr, CoNbZr, CoNiZr, FeCoZrBCu, NiFe, FeCo, FeAlN, (FeCo)N, FeAlSi, and FeTaC so that a spreading of the heating spot applied from the magnetic head for thermally-assisted recording to the film surface of the magnetic recording medium is suppressed, and that an SN is improved by arranging the magnetization direction of the perpendicularly written recording magnetization to become identical to a perpendicular direction, and realizing the higher recording density.

Abstract: A data device may have at least a magnetic lamination with a thermal retention structure deposited on a substrate and configured to maintain a predetermined temperature for a predetermined amount of time. Such predetermined temperature and amount of time may allow for the growth of a magnetic layer with a predetermined magnetic anisotropy.

Abstract: Provided are a method for production of a hard disk substrate capable of obtaining a smooth surface of a plating film by electroless NiP plating that is not degraded in, but exhibits corrosion resistance against, an acid solution and such a hard disk substrate.

Abstract: A hard drive platter comprises a substrate that includes glassy metal. At least one magnetic layer is arranged on the substrate. The glassy metal includes at least three of zirconium, titanium, nickel, copper, and/or beryllium. A perpendicular recording system comprises the hard drive platter. A hard disk drive comprises the hard drive platter. A computer comprises the hard disk drive. A digital camera comprises the hard drive platter. A portable media player comprises the hard drive platter. An insulating layer and/or an Aluminum layer may be located between the glassy metal substrate and the at least one magnetic layer.

Abstract: Disclosed are a glass substrate for an information recording medium, having excellent scratch resistance and a light weight and having high fracture toughness, the glass substrate having a fragility index value, measured in water, of 12 ?m?1/2 or less or having a fragility index value, measured in an atmosphere having a dew point of ?5° C. or lower, of 7 ?m?1/2 or less, or the glass substrate comprising, by mol %, 40 to 75% of SiO2, 2 to 45% of B2O3 and/or Al2O3 and 0 to 40% of R?2O in which R? is at least one member selected from the group consisting of Li, Na and K), wherein the total content of SiO2, B2O3, Al2O3 and R?2O is at least 90 mol %, and a magnetic information recording medium comprising a magnetic recording layer formed on the glass substrate.

Abstract: A thermally-assisted magnetic recording (TAMR) medium of the present invention includes: a magnetization direction arrangement layer on a substrate; and a magnetic recording layer on the magnetization direction arrangement layer, wherein the magnetization direction arrangement layer is made of at least one selected from a group consisting of Co, Zr, CoZr, CoTaZr, CoFeTaZrCr, CoNbZr, CoNiZr, FeCoZrBCu, NiFe, FeCo, FeAlN, (FeCo)N, FeAlSi, and FeTaC so that a spreading of the heating spot applied from the magnetic head for thermally-assisted recording to the film surface of the magnetic recording medium is suppressed, and that an SN is improved by arranging the magnetization direction of the perpendicularly written recording magnetization to become identical to a perpendicular direction, and realizing the higher recording density.

Abstract: A method of manufacturing a perpendicular magnetic recording medium and a substrate for the medium are disclosed, in which abnormal protrusions on an underlayer made of a Ni—P alloy are automatically eliminated while maintaining a flat surface with high accuracy on the underlayer, and appropriate texture traces remain to promote magnetization alignment in the vertical direction in a perpendicular magnetic recording medium without adversely affecting the magnetization alignment. In the method, texture processing is carried out on an underlayer made of a Ni—P alloy on a nonmagnetic base plate using a polishing tape while supplying mixed slurry of a surfactant and abrasive grains of polycrystalline diamond, and then, texture polishing is carried out on the underlayer processed by the texture processing, using a polishing tape while supplying slurry containing an abrasive material and an organic acid until the surface of the underlayer is polished to an arithmetic mean roughness Ra of at most 0.

Abstract: In one embodiment, a perpendicular magnetic recording medium includes a crystalline seed layer having a pseudo-hcp structure with stacking faults formed above a soft magnetic underlayer, a first interlayer comprising Ru and one of W, Ta, Mo, and Nb formed above the crystalline seed layer, a second interlayer formed above the first interlayer, and a magnetic recording layer formed above the second interlayer. The first interlayer has a W concentration between about 32 at % and 50 at %, Mo in a concentration between about 36 at % and 52 at %, Ta in a concentration between about 20 at % and 30 at %, or Nb in a concentration between about 7 at % and 30 at %. In another embodiment, a system includes a recording medium as described above, a magnetic head for reading from and/or writing to the medium, a head slider for supporting the head, and a control unit coupled to the head.

Abstract: A disk for a hard disk drive is provided. The disk comprises a substrate comprising aluminum, and a coating layer disposed over the substrate. The coating layer comprises an alloy of Ni, X1 and X2, wherein X1 comprises one or more elements selected from the group consisting of Ag, Au, B, Cr, Cu, Ga, In, Mn, Mo, Nb, Pb, Sb, Se, Sn, Te, W, Zn and Zr, and wherein X2 comprises either B or P, and wherein X1 and X2 do not comprise the same elements.

Abstract: A nanocomposite article that includes a single-crystal or single-crystal-like substrate and heteroepitaxial, phase-separated layer supported by a surface of the substrate and a method of making the same are described. The heteroepitaxial layer can include a continuous, non-magnetic, crystalline, matrix phase, and an ordered, magnetic magnetic phase disposed within the matrix phase. The ordered magnetic phase can include a plurality of self-assembled crystalline nanostructures of a magnetic material. The phase-separated layer and the single crystal substrate can be separated by a buffer layer. An electronic storage device that includes a read-write head and a nanocomposite article with a data storage density of 0.75 Tb/in2 is also described.

Abstract: It is an object of the present invention to provide a substrate for suspension reduced in the generation of cracks in an insulating layer at the boundary region between a region where a metal supporting substrate exists and a region where no metal supporting substrate exist.

Abstract: By improving sliding durability while ensuring a high SNR, an improvement in reliability and a further increase in recording density are to be achieved.

Abstract: The present invention is directed to the fabrication of rigid memory disks, including a metal plating composition which impedes deposition of non-metallic particles during a plating process. The plating composition includes at least one sulfated fatty acid ester additive, or mixtures or salts thereof, of formula: wherein R1 is selected from the group consisting of OH, OCH2, OCH2CH3, C1-C7 alkyl, linear or branched; R2 selected from H and C1-C7 alkyl, linear or branched; m=1 to about 5; n=2 to about 30; o=0 to about 10; M+ is a metal or pseudo metal ion or H+. The additive has a zeta potential which impedes deposit of non-metallic particles. The invention is further directed to a method for electroless plating utilizing the additive composition in a bath with at least a stabilizing agent, complexing agent and reducing agent and source of metal ions.

Abstract: The invention uses an adhesion layer of an amorphous alloy of aluminum. A first aluminum titanium embodiment of the amorphous adhesion layer preferably contains approximately equal amounts of aluminum and titanium (+/?5 at. %). A second embodiment of the amorphous adhesion layer preferably contains approximately equal amounts of aluminum and titanium (+/?5 at. %) and up to 10 at. % Zr with 5 at. % Zr being preferred. A third embodiment is aluminum tantalum preferably including from 15 to 25 at. % tantalum with 20 at. % being preferred. The most preferred compositions are Al50Ti50, Al47.5Ti47.5Zr5 or Al80Ta20. The adhesion layer is deposited onto the substrate. The substrate can be glass or a metal such as NiP-plated AlMg. The preferred embodiment of media according to the invention is for perpendicular recording and includes a magnetically soft underlayer deposited above the adhesion layer.

Abstract: A perpendicular recording magnetic media with a partially-oxidized cap layer combines a second oxide layer with a first cap layer to form the singular, partially-oxidized cap. The oxidized portion and the non-oxidized portion of the partially-oxidized layer are sputtered from a same target and have a same composition of metallic elements. The Ms of the oxidized portion is about twice as high as the non-oxidized portion. The oxidized portion has a thickness in the range of about 5 to 25 angstroms. The layer composition may comprise CoPtCrBTa, with a Cr at % of about 18-24%, Pt at about 13-20%, B at about 4-10%, and Ta at about 0-2%.

Abstract: A STT-RAM MTJ is disclosed with a MgO tunnel barrier formed by natural oxidation and containing an oxygen surfactant layer to form a more uniform MgO layer and lower breakdown distribution percent. A CoFeB/NCC/CoFeB composite free layer with a middle nanocurrent channel layer minimizes Jc0 while enabling thermal stability, write voltage, read voltage, and Hc values that satisfy 64 Mb design requirements. The NCC layer has RM grains in an insulator matrix where R is Co, Fe, or Ni, and M is a metal such as Si or Al. NCC thickness is maintained around the minimum RM grain size to avoid RM granules not having sufficient diameter to bridge the distance between upper and lower CoFeB layers. A second NCC layer and third CoFeB layer may be included in the free layer or a second NCC layer may be inserted below the Ru capping layer.

Abstract: A method for producing a double-sided evaporation film by forming metal-containing evaporation films on both surfaces of a non-magnetic plastic substrate film by an evaporation system with an evaporation drum, includes, in the following order: forming a metal-containing evaporation film on a first surface of the substrate film; forming an organic substance film on the metal-containing evaporation film; and forming a metal-containing evaporation film on a second surface of the substrate film, the second surface being opposite to the first surface.

Abstract: A glass substrate for a magnetic disk of the invention is a disk-shaped glass substrate for a magnetic disk where the substrate has a main surface and end face and is subjected to chemical reinforcement treatment, and is characterized in that the penetration length in the uppermost-portion stress layer on the main surface is 49.1 ?m or less, and that assuming that an angle between the main surface and compressive stress in the stress profile by a Babinet compensator method is ?, a value y of {12·t·ln(tan ?)+(49.1/t)} is the penetration length in the uppermost-portion stress layer or less.

Abstract: A substrate for suspension 10 comprises a metallic substrate 1, an insulating layer 2 formed on the metallic substrate 1, a conductor layer 3 formed on the insulating layer 2, and a cover layer 4 covering the conductor layer 3. The insulating layer 2 and the cover layer 4 are formed from different materials, whose coefficients of hygroscopic expansion are in the range between 3×10?6/% RH and 30×10?6/% RH. The difference between the coefficients of hygroscopic expansion of the two materials is 5×10?6/% RH or less.

Abstract: A perpendicular magnetic recording medium, which includes a nonmagnetic substrate, and a first underlayer in the form of a soft magnetic under-layer (SUL), a second underlayer, an intermediate layer, a magnetic recording layer, a protective layer, and a lubricant layer sequentially laminated on the nonmagnetic substrate. The SUL has a plurality of SUL layers including a type-A SUL layer, a plurality of type-B SUL layers including at least two adjacent type-B SUL layers, and a nonmagnetic metal spacer layer disposed between the two adjacent type-B SUL layers. The type-A SUL layer may include a material selected from Co, Fe and Ni, a material selected from Cr, V and Ti, and a material selected from W, Zr, Ta and Nb. Each of the type-B SUL layers is in antiferromagnetic coupling, and may include a material selected from Co, Fe and Ni, a material selected from Cr, V and Ti, and a material selected from W, Zr, Ta and Nb.

Abstract: A magnetic recording medium substrate has a polyester film having metallic oxide-containing layers (layers M) formed on both the surfaces, one layer on each surface, the layers M having a thickness of 50 to 200 nm each, characterized in that the magnetic recording medium substrate has a total light transmittance of 0 to 75% and a surface resistivity of 1×102 to 1×1013? on each surface.

Abstract: Not only chemical durability of a glass substrate for an information recording medium is improved, but also no deformation of the substrate and no alteration of substrate characteristics are to be made. A chemical treatment layer formed on the glass substrate surface is made thicker toward a large surface roughness portion of the glass substrate, prior to being subjected to a chemical treatment, from a small surface roughness portion of the glass substrate. Layer thickness D of the resulting chemical treatment layer preferably satisfies the following inequality (1) in view of acquisition of chemical durability. 100 Ra?D?3000 Ra??(1) wherein Ra is surface roughness of the glass substrate prior to being subjected to the chemical treatment.

Abstract: A magnetic recording media with a multilayer structure and methods for forming the media are described. The magnetic recording media includes a substrate, an underlayer on top of the substrate and a magnetic layer over the underlayer. The underlayer includes a CrN film formed by sputter depositing chromium in the presence of nitrogen or nitrogen containing compounds.

Abstract: Epitaxial ferroelectric and magnetic recording structures having graded lattice matching layers are disclosed. A single crystal material such as Si may be used as a substrate material upon which the graded lattice matching layers are deposited. The lattice matching layers may comprise metals and metal alloys, or may comprise oxides doped with selected elements or deposited under different oxygen pressures. A recording layer, such as ferroelectric lead zirconium titanate or a magnetic Fe/Pt multilayer structure, is deposited on the graded lattice matching layers.

Abstract: A silicon substrate for a magnetic recording medium in which the substrate has a chamfered surface between its data-carrying surface (surface) having layers including a magnetic layer and its outer peripheral end surface (straight surface) is provided. The silicon substrate is characterized in that a dub-off value at an outer peripheral side of the data-carrying surface is not more than 120 ? wherein when a first position (A) is a point on the data-carrying surface radially and inwardly positioned at 1 mm from the outer peripheral end surface of the substrate, a second position (B) is a point on the data-carrying surface radially and inwardly positioned further at 1.

Abstract: To provide a glass for an information recording media substrate, which is excellent in weather resistance. A glass for an information recording media substrate, which comprises, as represented by mol % based on oxide, from 61 to 66% of SiO2, from 11.5 to 17% of Al2O3, from 8 to 16% of Li2O, from 2 to 8% of Na2O, from 2.5 to 8% of K2O, from 0 to 6% of MgO, from 0 to 4% of TiO2 and from 0 to 3% of ZrO2, provided that Al2O3+MgO+TiO2 is at least 12%, and Li2O+Na2O+K2O is from 16 to 23%, wherein in a case of where B2O3 is contained, its content is less than 1%. The above glass for an information recording media substrate, wherein when the glass is left under steam atmosphere at 120° C. at 0.2 MPa for 20 hours, and the amount of Li, the amount of Na and the amount of K, which precipitate on a surface of the glass are represented as CLi, CNa and CK respectively, CNa is at most 0.7 nmol/cm2, and CLi+CNa+CK is at most 3.5 nmol/cm2.

Abstract: In this invention, etching is not performed in the step of planarizing a polycrystalline Si wafer, but only mechanical grinding is performed for planarization. This is because, since the etching rate is crystal-face dependent, etching of the polycrystalline Si wafer unavoidably results in formation of steps due to different crystal face orientations of individual crystal grains exposed on a surface of the wafer, thus hindering precision surface planarization. Subsequently, the Si wafer surface is coated with an oxide film to form an Si wafer with oxide film prior to the final polishing stage and then a surface of the oxide film is planarized, to give a planar substrate (i.e., Si substrate with oxide film) having no step on the surface thereof.

Abstract: The proportion of {100} crystal faces, the polish rate of which is relatively high during crystal machining, and/or the proportion of {111} crystal faces, the polish rate of which is relatively low during crystal machining, to the total area (S0) of a substrate surface, is set to fall within an appropriate range. Specifically, the proportion of the total area (S{100}) of the {100} crystal faces among crystal faces of individual crystal grains which appear on a major surface of a polycrystalline silicon substrate to the total area (S0) of the substrate surface, is set not less than 10% and less than 50%. Such crystal face selection makes it possible to reduce the scale of “steps” formed due to the crystal face index dependence of polish rate, thereby to give a planar and smooth substrate surface.

Abstract: Provided is a surface-treated substrate in which the roughness of the surface of the substrate is controlled. The surface-treated substrate can form a magnetic recording medium in which head flying stability is maintained and which has a magnetic film that can achieve high recording densities. Also provided is a method for roughening the surface of the substrate. More specifically, provided is a surface-treated silicon substrate for a magnetic recording medium in which a surface used for forming a recording layer has 40 to 1000 protrusions per 1 ?m2 with a maximum height of 10 nm or less and an average roughness of 0.3 to 2.0 nm, and in which there are no defects or spots on any of the surface. Furthermore, provided is a method for manufacturing the surface-treated silicon substrate for the magnetic recording medium, comprising a step of etching a surface of a silicon substrate, wherein ultrasound is applied to the surface of the silicon substrate with the substrate shaken or rotated.

Abstract: The disclosure provides a magnetic film which includes a titania nanosheet which is formed on a transparent substrate and contains a layered titanium oxide in which at least one magnetic element is substituted for a Ti lattice position, the titanium oxide being expressed by a formula: Ti2-xMxO4 where M is at least one kind of transition metal elements chosen from among V, Cr, Mn, Fe, Co, Ni, and Cu, and 0<x<2, a dispersant surrounding the nanosheet, and a water-soluble organic compound.

Abstract: A disk substrate for a perpendicular magnetic recording medium comprises a disk base member, a soft magnetic layer formed on the disk base member, and a protection layer formed on the soft magnetic layer. The soft magnetic layer and the protection layer are deposited by sputtering. A perpendicular magnetic recording disk comprises the above-mentioned disk substrate and at least a perpendicular magnetic recording layer formed thereon. The perpendicular magnetic recording layer is deposited on the disk substrate by sputtering after the disk substrate is heated.

Abstract: A soft magnetic under layer (SUL) is formed on a non-magnetic substrate by an electroless plating method. The SUL formed by plating is subjected to magnetic field heat treatment on conditions that the heat treatment temperature is 150° C. to 350° C., a magnetic field applied to the substrate has a strength of 50 oersteds (Oe) or more, and the treatment time is selected within a range of five minutes to ten hours. Through the magnetic field heat treatment, magnetic anisotropy is obtained with a difference (?H=Hd?Hc) of 5 oersteds (Oe) or more in terms of absolute value between a magnetization saturation magnetic field strength (Hd) in the in-plane radial direction of a soft magnetic film and a magnetization saturation magnetic field strength (Hc) in the in-plane circumferential direction of the soft magnetic film, and the magnetic anisotropy is symmetric with respect to the axis of the substrate.

Abstract: The invention provides a magnetic recording medium and a method of manufacturing the magnetic recording medium, in which a high density and good storage stability can be achieved by giving anisotropy in shape to a magnetic substance. A plan shape of the magnetic substance in the magnetic recording medium, which appears on the recording surface side, is an ellipse that is present within a rectangle and has a minor axis with a length equal to a short side of the rectangle. A quadrilateral defined by four intersects of two adjacent vertical rows and two adjacent horizontal rows, each of these rows comprising a plurality of pores, has a rectangular or rhombic shape.

Abstract: A member of supporting magnetic disc substrates is provided, comprising a ceramic sinter containing a ceramic component and at least one conductive component selected from a group consisting of iron, niobium, tin zinc, copper, nickel, cobalt, and chromium, wherein the ceramic sinter has conductive aggregates on its peripheral surface. In the member, the ceramic component may be forsterite and the conductive component is iron oxide, wherein the ceramic sinter comprises a main phase of 2MgO.SiO2 and a secondary phase of at least one of MgFe2O4, Fe3O4 and Fe2O3.

Abstract: A method of manufacture of thin film magnetic disks and other useful articles of similar planar geometry in which a non-magnetic layer is first deposited on one or both sides of the disk or article substrate to mask chemical and mechanically induced heterogeneities introduced by pre-polishing to achieve a smooth finish, typically resulting in cold-working of the surface, and to also bind to the substrate and is then coated with a thin layer of metal selected to either reactively or catalytically initiate smooth, electroless deposition of a non-magnetic nickel alloy which is subsequently polished and coated with additional thin layers to provide magnetic read-write capability. A disk drive using one or more of such disks is provided.