Fuji Electric Co., Ltd.

Fuji Electric Device Technology Co., Ltd.

Hiroto Kikuchi

Takehito Shimatsu

Akira Furuta

Hiroyasu Kataoka

Tomohiro Moriya

Hitoshi Nakata

Shinji Uchida

Tsuyoshi Yoshizawa

The purpose of the present invention is to provide a magnetic recording medium capable of reducing the surface roughness of the magnetic recording layer without adversely affecting the magnetic properties of the magnetic recording layer. The magnetic recording medium of the present invention includes a substrate, a seed layer on the substrate, and a magnetic recording layer on the seed layer, wherein the seed layer has a structure of: (a) a spinel structure consisting of Mg, Cr and O; (b) a spinel structure consisting of Zn, Fe and O; or (c) an inverse spinel structure consisting of Mg, Ti and O.

Magnetic recording medium

The present invention aims at providing a magnetic recording medium capable of realizing lowering of recording temperature. A magnetic recording medium comprises a substrate, and a magnetic recording layer comprising a first magnetic layer and a second magnetic layer, in which the second magnetic layer comprises an FePtRh ordered alloy, and the first magnetic layer has Ku at room temperature larger than Ku of the second magnetic layer at room temperature.

The purpose of the invention is to provide a magnetic recording medium in which the surface roughness of the magnetic recording layer can be reduced without deterioration of the magnetic properties of the magnetic recording layer. The magnetic recording medium of the present invention includes a substrate, a seed layer on the substrate, and a magnetic recording layer on the seed layer, wherein the seed layer contains Mn, Cr, and O, and has a spinel structure.

The present invention provides a magnetic recording layer that has a high magnetic anisotropy constant Ku and a low Curie temperature Tc, as well as a magnetic recording medium that incorporates such a magnetic recording layer. The magnetic recording medium of the present invention includes a nonmagnetic substrate and a magnetic recording layer containing an ordered alloy. The ordered alloy may contain at least one element selected from the group consisting of Fe and Ni; at least one element selected from the group consisting of Pt, Pd, Au, Rh and Ir; and Ru.

A method for manufacturing perpendicular magnetic recording medium which includes magnetic recording layer having desired film thickness while maintaining high magnetic anisotropy and having more homogenized magnetic characteristics. The method includes: (A) preparing non-magnetic substrate; (B) laminating magnetic recording layer on the substrate; and (C) heating the substrate on which the magnetic recording layer is laminated to a temperature of 400 to 600&#xb0; C. The step (B) includes at least forming a first magnetic recording layer and a second magnetic layer thereon. The first layer has a granular structure including a first magnetic crystal grain constituted by an ordered alloy surrounded by a first non-magnetic grain boundary constituted by carbon, and the second layer has a granular structure including a second magnetic crystal grain constituted by an ordered alloy surrounded by a second non-magnetic grain boundary constituted by a non-magnetic material constituted by boron and carbon.

Method for manufacturing perpendicular magnetic recording medium

A perpendicular magnetic recording medium includes at least a nonmagnetic substrate and a magnetic recording layer. The magnetic recording layer is constituted by a plurality of layers that includes at least a first magnetic recording layer and a second magnetic recording layer. The first magnetic recording layer has a granular structure that includes first magnetic crystal grains and first nonmagnetic crystal grain boundaries surrounding the first magnetic crystal grains. The first magnetic crystal grains include an ordered alloy, and the first nonmagnetic crystal grain boundaries are constituted by carbon. The second magnetic recording layer has a granular structure that includes second magnetic crystal grains and a second nonmagnetic crystal grain boundaries that surround the second magnetic crystal grains. The second magnetic crystal grains include an ordered alloy, and the second nonmagnetic crystal grain boundaries are constituted by a carbon-containing nonmagnetic material.

Perpendicular magnetic recording medium

A system and method for magnetic transfer. A magnetic transfer device includes a plurality of pairs of magnetic field generating units that apply a magnetic field to a contact body which includes a master disk in close contact with a magnetic recording medium, wherein the master disk has a pattern of preformatted signals. The magnetic field generating units, falling within a specified length range, are moved in synchrony at a predetermined speed in the directions of the outer periphery while the contact body is caused to rotate by a rotation drive unit. The system and method provide a magnetic transfer method and a magnetic transfer device that, by reducing the area of magnetic field generating units that apply a transfer magnetic field, can reduce an attractive force (or repulsive force) between the magnets, and furthermore, shorten a processing time for the transfer.

Magnetic transfer method and magnetic transfer device

A method of drawing a pattern for magnetic transfer on a substrate, including the steps of rotating the substrate and scanning the substrate, by an electron beam, in a circumferential direction thereof, deflecting, using a deflection signal, the electron beam in a radial direction thereof, and switching irradiation of the electron beam on and off, so as to create the pattern of a plurality of dots.

Method of drawing a pattern for magnetic transfer

A magnetic transfer device and method are provided. A magnetic field generating structure comprises a pair of permanent magnets connected to a return yoke. Respective magnetic poles of the magnets, of a different polarity from one another, oppose each other with a conjoined body disposed therebetween. The magnetic field generating structure is moved from a position at an outer periphery of the conjoined body, to a position at an inner periphery of the conjoined body, and then moved from the position at the inner periphery across the conjoined body toward the outer periphery, to a position outside of the conjoined body. The return yoke is positioned at a radially more outward position, toward the outer periphery, than are the permanent magnets. The movement of the magnetic field generating structure is carried out while maintaining a constant distance from the rotating conjoined body.

Magnetic transfer device and magnetic transfer method

A master disk for magnetic transfer of a reference servo signal in a spiral mode, having a pattern including a plurality of dots groups, which are disposed at different radial positions of the master disk with a first pitch, and correspond to the reference servo signal in the spiral mode. Each of the plurality of dot groups includes a plurality of dots, successively disposed with a second pitch along a circumferential direction of the master disk at a same one of the radial positions. Each of the plurality of dots is of a ferromagnetic material, and has four sides, two opposing sides thereof extending in the circumferential direction, and the other two opposing sides thereof extending in a radial direction of the master disk.

Master disk for magnetic transfer, a method of drawing a magnetic transfer pattern, and a magnetic recording medium having a transferred magnetic transfer pattern

A defect inspection method and device for a perpendicular magnetic recording medium that has discrete recording tracks and grooves between recording tracks, including DC demagnetizing the perpendicular magnetic recording medium, detecting a reproduced signal from the perpendicular magnetic recording medium after the DC demagnetizing, removing output fluctuation components caused by the grooves from the reproduced signal using a filter with a prescribed cutoff frequency and separating a peak output of the reproduced signal, comparing the peak output with a prescribed reference signal, and identifying a location where the peak output exceeds the reference signal as a defect location. The method further includes performing an envelope-detection on the reproduced signal, detecting a pre-format region in the perpendicular magnetic recording medium using the envelope-detection result, masking the detected pre-format region, and detecting the defect location in a region outside the masked pre-format region in the perpendicular magnetic recording medium.

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Sendai, Japan

Hiroto Kikuchi