38results about "Magnetic field orientation" patented technology

A perpendicular magnetic recording disk having a single domain exchange-coupled laminated soft magnetic underlayer (SUL) is disclosed. The SUL is a combination synthetic anti-parallel coupled SUL structure, which has the product (Mst) of saturation magnetization and film thickness of the middle ferromagnetic layer less than the sum of the Mst of the bottom and top ferromagnetic layers. Subjected to a post radial field reset process, this SUL provides single domain state. Moreover, both robustness of stray fields and low permeability are obtained while keeping excellent corrosion resistance and cost effective manufacturability.

Embodiments of the invention provide a perpendicular magnetic recording medium improved for fly ability, high in read signal quality, and capable of suppressing magnetic decay of recorded magnetization to be caused by stray fields. In one embodiment, a perpendicular recording layer is formed over a substrate with a soft magnetic underlayer therebetween, then an amorphous or nano-crystalline layer is formed between the substrate and the soft magnetic underlayer. The soft magnetic underlayer includes first and second amorphous soft magnetic layers, as well as a nomnagnetic layer formed between those first and second amorphous soft magnetic layers. The first and second amorphous soft magnetic layers are given uniaxial anisotropy in the radial direction of the substrate respectively and coupled with each other antiferromagnetically.

A magnetic recording medium has a recording layer, disposed above a surface of a substrate and made of hard magnetic nano-particles. The hard magnetic nano-particles are made of an alloy having as a main component an element selected from a group consisting of FePt, FePd and CoPt, and the hard magnetic nano-particles have axes of easy magnetization oriented in a direction approximately perpendicular to the surface of the substrate.

A magnetic annealing device for inserting a recording medium 1 provided with an axial hole formed at a center thereof and having a disk shape into a chamber 10 and applying a heat treatment to the recording medium 1 in a magnetic field is provided with a magnetic circuit for forming a magnetic field in the chamber 10, the magnetic circuit comprises a pair of magnets 4 and 5 disposed with a distance therebetween along an axial direction of the axial hole and having magnetic fields directionally opposed to each other and a first ferromagnetic substance 6 disposed between the pair of magnets 4 and 5, wherein the recording medium 1 to be heat-treated is disposed at an intermediate position between the pair of magnets 4 and 5 facing each other in the state in which the first ferromagnetic substance 6 is inserted into the axial hole. A second ferromagnetic substance 7 having a ring shape is preferably disposed in a periphery of the recording medium 1.

The invention relates to a method for preparing the FePt, CoPt vertical magnetic record film, wherein said method comprises: (1) preparing FePt (M) or CoPt (M) film whose crystal is cubic, while M is one of C, P, B non-metal elements or one of Ag, Cu, Sn, Pb, Bi, Ga, and In whose fusion point is lower than Fe; (2) arranging FePt (M) or CoPt (M) film into magnetic film whose direction is vertical to the film; then processing laser thermal treatment on the film. The invention can make magnetic axle of iron magnetic crystal of film be arranged vertically to the film. And it ahs simple process and easy control, while it can confirm the film fineness.

Perpendicular magnetic recording media enabling high-density recording and reproduction of information, as well as a production process thereof, and a magnetic recording and reproducing apparatus, are provided. Perpendicular magnetic recording media, having at least a soft magnetic underlayer and perpendicular magnetic recording layer on a disc-shaped nonmagnetic substrate, in which the soft magnetic underlayer has at least two soft magnetic layers, and Ru or Re between the two soft magnetic layers, are provided; the easy axis of magnetization of the soft magnetic underlayer has a desired direction; the easy axis of magnetization of the soft magnetic underlayer is substantially distributed in a direction except a radial direction of the nonmagnetic substrate, and, the bias magnetic field of the antiferromagnetic coupling in the direction of the easy axis of magnetization of the soft magnetic underlayer is 10 Oersteds (790 A/m) or greater.

Provided are a double-layer perpendicular magnetic recording medium having a high medium S/N at an areal recording density of 50 Gbits or more per square inch, and a magnetic storage apparatus having excellent reliability with a low error rate. The perpendicular magnetic recording medium is formed by sequentially laminating a domain control layer, an amorphous soft magnetic underlayer, an intermediate layer, and a perpendicular recording layer on a substrate. The domain control layer is a triple-layer film formed by laminating a first polycrystalline soft magnetic layer, a disordered antiferromagnetic layer, and a second polycrystalline soft magnetic layer from a substrate side.

A magnetic recording medium and a method of manufacturing the same which serve for stable head behavior and efficient recording of servo information. In each servo area, a magnetic layer is separated into a plurality of servo pattern unit parts for forming a predetermined servo pattern and a plurality of servo pattern gap filling parts patterned to fill gaps between the plurality of servo pattern unit parts partly. The servo pattern unit parts and the servo pattern gap filling parts are formed in different sizes so as to have different magnetic properties.

The invention discloses a CoCrPt series alloy sputtering target and film and a preparation method thereof. The CoCrPt series alloy sputtering target comprises an element B, wherein the content of the element B is 0-20 atomic percent; the alloy target comprises a Co-enriched phase and a B-enriched phase; the B-enriched phase is uniformly distributed in the Co-enriched phase; the average grain size of the Co-enriched phase is 20-50mu m; and the average grain size of the B-enriched phase is 0-20mu m. The method for preparing the CoCrPt series alloy sputtering target comprises the following steps: (1) performing vacuum melting; (2) performing hot isostatic pressure; (3) performing thermal machining; and (4) performing cold machining. The invention also discloses a magnetic recording medium prepared by using the CoCrPt series alloy sputtering target. The magnetic recording medium comprises a substrate layer, an adhesive layer, a soft magnetic layer, an intermediate layer and a magnetic recording layer, wherein the coercive force of the magnetic recording medium is 3000-5000Oe; and the squareness is 0.80-0.95. The CoCrPt series alloy sputtering target is uniform in chemical components and small in deviated nominal composition, and the technical problems in a conventional preparation process that rolling cracking is caused, the yield is low, the mount of deviated nominal composition of the chemical components of the alloy target is large, the content of harmful impurities is extremely high are solved.

An initialization magnetic field (Hi) as an external magnetic field is applied in a direction crossing (perpendicularly) the surface of the substrate 10 to initialize the medium 1, so that the first magnetic film 11 and the second magnetic film 12 can be initialized simultaneously. In this method for initializing a medium, the magnetization direction of the initialization magnetization H1i at the first magnetic film 11 and the magnetization direction of the initialization magnetization H2i at the second magnetic film 12 accord with each other with regard to a direction crossing the substrate 10.

A method of manufacturing flexible magnetic tape having a permanently structured magnetic characteristic which varies from place to place in two different directions in the plane of the tape, includes:—a) coating a flexible substrate with a slurry having anisotropic magnetic particles; b) moving the substrate and slurry coating relative to a first magnetic field having a field strength which varies with time in a first direction, thereby selectively orienting the particles in areas spaced apart in a first direction; c) subsequently moving the substrate and slurry coating relative to a second magnetic field having a field strength which varies with time in a second direction making an oblique angle with the first direction, such that the magnetic particles are selectively oriented in spaced areas in both the first and further directions, and d) solidifying the slurry to fix the particles in place.

In a perpendicular magnetic recording medium and a method of manufacturing the same, a first magnetic recording layer includes first magnetic crystal grains and a first non-magnetic portion containing carbon, a second magnetic recording layer includes second magnetic crystal grains and a second non-magnetic portion containing ZnO, a third magnetic recording layer includes third magnetic crystal grains and a third non-magnetic portion containing carbon, a film thickness t2 of the second magnetic recording layer is 0.1 nm to 7.0 nm, a volume fraction x2 of the second non-magnetic portion in the second magnetic recording layer at completion of formation is 0.20 to 0.90, a film thickness t3 of the third magnetic recording layer is 0.5 nm to 4.0 nm, a volume fraction x3 of the third non-magnetic portion in the third magnetic recording layer is 0.20 to 0.70, and (t2/t3)×(x2/x3) is 0.30 to 1.20.

The invention discloses a method for solving a super-paramagnetic state of magnetic recording particles, which is characterized in that: a layer of anti-ferromagnetic material capable of pinning the magnetic moment thereof is wrapped outside the magnetic recording particles, and the anti-ferromagnetic material is coupled with the magnetic recording particles through an interface magnetic moment to ensure that the magnetic moments of the magnetic recording particles are arranged along the same direction. The method can overcome thermal disturbance under a nano-scale of the magnetic particles, improve uniaxial anisotropy energy of the magnetic particles artificially, and solve the problem of unstable records in the super-paramagnetic state.

This invention relates to one magnetic medium and its process method, wherein, the magnetic record medium comprises one magnetic record layer comprising several carbon nanometer balls and several magnetic particles in discrete status by carbon nanometer ball with same direction; magnetic record medium makes magnetic particles in discrete status by use of carbon nanometer covered particles helpful for depressing media mixture signals between particles an the nanometer ball has small radium as nanometer.

In a magnetic circuit for providing magnetic anisotropy in the in-plane radial direction of a soft magnetic under layer, magnets for perpendicular magnetization are respectively provide on the north and south poles of a magnet for horizontal magnetization. When magnetic circuits configured thus are stacked in a plurality of stages, a magnetic field (air-gap magnetic field) formed in a gap between the magnetic circuits is superimposed by magnetic fields from the magnets for perpendicular magnetization as well as a magnetic field from the magnet for horizontal magnetization (in-plane magnetization). The pole faces of the magnets for perpendicular magnetization are disposed closer to the gap between the magnetic circuits, so that a stronger magnetic field can be formed in the gap.

A method and an apparatus for manufacturing a perpendicular magnetic recording medium are provided which can easily demagnetize a magnetic layer with a high coercivity. The method includes: forming a magnetic layer on a substrate; applying magnetic fields parallel to the surface of the magnetic layer having a coercivity reduced below the intensity of said magnetic field by heating of the magnetic layer; and removing said magnetic field.

The invention discloses a device applied to magnetic recording medium orientation and belongs to the field of permanent magnet materials. The device comprises a first permanent magnet device forming a first permanent magnet circuit and a second permanent magnet device forming a second permanent magnet circuit, wherein a channel is arranged between the second permanent magnet device and the first permanent magnet device, the first permanent magnet circuit and the second permanent magnet circuit are symmetrically arranged, parallel permanent magnet fields are formed in the channel, and a magnetic recording medium is orientated when passing through the channel. The device uses a permanent magnet material as a constant magnetic source, orientates the magnetic recording medium, requires no electromagnetic field and is energy-saving and environment-friendly.

The magnetic recording medium provided is produced by forming a substrate having a nanoparticle layer comprising an array of nanoparticles, and an organic compound between said array of nanoparticles; irradiating the nanoparticle layer with an infrared beam to magnetize the nanoparticles; applying a magnetic field to the nanoparticle layer to orient easy axis of magnetization of the magnetic nanoparticles in a substantially uniform direction; and irradiating the nanoparticle layer with an ultraviolet beam to bind said organic compound to thereby produce a magnetic recording medium wherein easy axis of magnetization of the nanoparticles has been oriented in a direction substantially parallel to a direction at a particular angle with the substrate. The resulting magnetic recording medium experiences no deterioration of the underlying layer or the soft magnetic layer, and exhibits good magnetic properties.