Fujitsu Corporation

Showa Denko K.k.

Ryoichi Mukai

Hiroto Takeshita

Wataru Yamagishi

Kazuo Kobayashi

Kazunori Yamanaka

Takuya Uzumaki

Motoo Nakano

Michiko Takei

Kazumasa Shimoda

Masako Iizuka

A perpendicular magnetic recording medium comprises a soft-magnetic backing layer formed on a substrate, an orientation control layer formed on the soft-magnetic backing layer, a first foundation layer of a continuous film of Ru or a Ru alloy formed on the orientation control layer, a second foundation layer including a plurality of crystal grains of Ru or a Ru alloy formed on the first foundation layer with a gap separating the plurality of crystal grains from each other, and a recording layer including a plurality of magnetic particles formed on the second foundation layer respectively in correspondence to the plurality of crystal grains, each of the magnetic particles having an easy axis of magnetization in a direction generally perpendicular to a substrate surface, and a non-magnetic grain boundary phase isolating said plurality of magnetic particles from each other, wherein the first foundation layer comprises a plurality of crystal grains formed in contact with each other at respective grain boundaries, one of the plurality of crystal grains constituting the second foundation layer being formed in correspondence to one of the plurality of crystal grains constituting the first foundation layer, and wherein there are provided a plurality of nuclei at an interface between the crystal grain of the second foundation layer corresponding to the one crystal grain of the plurality of crystal grains constituting the first foundation layer and the orientation control layer.

Perpendicular magnetic recording medium and manufacturing method thereof, magnetic recording apparatus

A perpendicular magnetic recording medium is disclosed that includes a recording layer having a columnar granular structure possessing an appropriate diameter distribution and uniform arrangement of magnetic particles. The perpendicular magnetic recording medium includes a substrate, and a soft-magnetic underlayer, a seed layer, an underlayer, a recording layer, a protection film, and a lubrication layer stacked on the substrate in order. The underlayer includes granular crystals formed from Ru or a Ru alloy and interstices separating the granular crystals from each other so as to isolate individual granular crystals. A continuing film formed from Ru or Ru alloys may be provided below the underlayer.

Perpendicular magnetic recording medium, method of producing the same, and magnetic storage device

A perpendicular magnetic recording medium is disclosed that includes a substrate; a soft magnetic underlayer formed on the substrate; a seed layer of an amorphous material formed on the soft magnetic underlayer; an oxidation prevention layer formed on the seed layer; an underlayer formed on the oxidation prevention layer, the underlayer including multiple crystal grains formed of Ru or a Ru alloy having an hcp crystal structure, and a first air gap part configured to separate the crystal grains from each other; and a recording layer formed on the underlayer, the recording layer including multiple magnetic particles having a magnetocrystalline easy axis in a direction substantially perpendicular to the surface of the substrate, and one of a second air gap part and a non-magnetic non-solid-solution phase, the one being configured to separate the magnetic particles from each other. The oxidation prevention layer includes a noble metal element other than Ru.

Perpendicular magnetic recording medium, method of manufacturing the same, and magnetic storage unit

A higher value of an anistropic magnetic feild can be acquired by using a magnetic material where Cr is not added as a material of a magnetic layer on which magnetic data is recorded. A magnetic recording medium can be manufactured through the processes of laminating an underlayer cosisting opf Cr-based non-magnetic material on a substrate, and then laminating, on this underlayer, a magnetic layer consisting of an alloy of at least one kind of non-magnetic material that is different from Cr and Co.

Magnetic recording medium, method of manufacturing the same medium and magnetic disc drive

Magnetic crystalline grains are spaced from each other on a base layer a polycrystalline structure. The magnetic crystalline grains are made of an ordered alloy. The ordered alloy serves to ensure the crystalline magnetic anisotropy energy larger than that of Co alloy in the magnetic crystalline grains. Such crystalline magnetic anisotropy energy reaches over 1&#xd7;10J/m, for example. A sufficient magnetic crystalline magnetic anisotropy energy serves to reliably maintain the magnetization in finely structured magnetic crystalline grains. The ordered alloy may have the L1structure, for example. The ordered alloy may include of FePt(atom %), FePd(atom %), CoPt(atom %), and the like.

Polycrystalline structure of ordered alloy and method of making the same

First magnetic crystalline grains are located at spaced positions on the surface of a base layer in a polycrystalline structure film. Magnetic interaction can reliably be prevented between the adjacent first magnetic crystalline grains. An amorphous material or a non-magnetic material covers over the first magnetic crystalline grains. An orientation controlling layer covering over the first magnetic crystalline grains and the amorphous or non-magnetic material on the base layer. Second magnetic crystalline grains are located at spaced locations on the surface of the orientation controlling layer. The orientation controlling layer serves to set the orientation in a predetermined direction in the second magnetic crystalline grains. Since the orientation of the magnetic crystalline grains can be aligned in a predetermined direction, the magnetic field of a sufficient intensity can be leaked out of the polycrystalline structure film.

Polycrystalline structure film and method of making the same

A magnetic recording medium includes an underlayer formed on a substrate and a magnetic layer formed by epitaxial growth on the underlayer. The underlayer is made of Cr based substance, and the magnetic layer is made of Co based magnetic substance. The magnetic layer further includes a plurality of layers, each made of Co based alloy including at least one of oxide and nitride as additional content.

Magnetic recording medium and fabrication method thereof

A layered polycrystalline structure includes a seed crystal or Cr layer containing non-magnetic Cr atoms. A non-magnetic crystal layer such as a CoCrlayer is formed on the exposed surface of the seed crystal layer. A magnetic crystal layer such as a coPtlayer is formed on the exposed surface of the non-magnetic crystal layer. Heat treatment induces the diffusion of the Cr atoms along the grain boundaries within the magnetic crystal layer. Walls of a non-magnetic material can be established along the grain boundaries in the magnetic crystal layer. The diffusion of the Cr atoms can sufficiently be suppressed within the lattices of the magnetic crystal grains. Generation of an incomplete non-magnetic region can thus be restrained to the utmost within the magnetic crystal layer. Noise can be reduced in reproduction of a magnetic information data.

Layered polycrystalline structure and method of making the same

A magnetic recording medium comprising a non-magnetic base and a non-magnetic underlayer and a magnetic layer formed in that order on the base, the uniderlayer comprises a non-magnetic polycrystalline material and the magnetic layer comprises magnetic CoCr-based alloy particles, wherein the planar size of the magnetic alloy particles is defined by the planar size of the polycrystalline particles composing the underlayer, and is no greater than 20 nm. The magnetic recording medium is useful for HDDs in particular, having a very high magnetic coercive force and being capable of high recording density.

Magnetic recording medium and production process thereof

A magnetic hard disk having magnetic tracks for storing data which is read or written by a magnetic head floating immediately above the magnetic track while the magnetic hard disk is rotating, and the magnetic head rests on the magnetic hard disk while the magnetic hard disk is not rotating. One aspect of the present invention is that the magnetic hard disk comprises a non-magnetic substrate having a plurality of banks and grooves alternately and concentrically arranged thereon, a magnetic film formed on each of the banks, and non-magnetic material formed on an entire surface of the substrate all over the banks and grooves such that roughness of the upper surface of the non-magnetic material is in a range between 0.5 nm and 3 nm.

Method for manufacturing a magnetic hard disk having concentric magnetic tracks with flat surface

A magnetic hard disk has magnetic tracks for storing data, which is read or written by a magnetic head floating immediately above the magnetic track while the magnetic hard disk is rotating. The magnetic head rests on the magnetic hard disk while the magnetic hard disk is not rotating. The magnetic hard disk comprises a non-magnetic substrate having a plurality of banks and grooves alternately and concentrically arranged thereon, a magnetic film formed on each of the banks, and a non-magnetic material formed on an entire surface of the substrate all over the banks and grooves such that roughness of the upper surface of the non-magnetic material is in a range between 0.5 nm and 3 nm.

Magnetic hard disk having concentric magnetic tracks with flat surface and fabrication method thereof

A magnetic recording medium using a substrate, such as a glass substrate, and having, in combination, superior magnetic and magnetic recording properties and good adhesion of a magnetic layer to the substrate. The magnetic recording medium has an intermediate layer of chromium between the substrate and an underlayer of Ni-based non-magnetic material on which a magnetic layer of Co-based magnetic alloy is superimposed. A method of producing the magnetic recording medium is also disclosed, wherein each of the layers is formed by a sputtering process at a sufficient pressure to promote granular growth of crystals of the layer.

Magnetic recording media and method of producing the same

A magnetic recording medium has a substrate of a disk shape having a non-magnetic surface and a through hole formed at the central area of the substrate, and a plurality of dispersed island regions made of magnetic material and directly formed on the non-magnetic surface. The size of each of the island regions is a single magnetic domain size or finer of the magnetic material. The island regions are formed by cohering atoms of a magnetic film formed by sputtering.

Magnetic recording medium containing fine magnetic crystal grains and its manufacture

The present invention discloses a production process for a hard disk magnetic recording medium in which post-annealing is performed after vacuum deposition of a non-magnetic base layer and magnetic metal polycrystalline layer on a substrate without forming a protective layer and without destroying the vacuum.

Production process for a hard disk magnetic recording medium

A process of producing a semiconductor device, which includes the steps of: forming an insulating film on a substrate; then etching the insulating film to form an opening through which the substrate is exposed; and then irradiating a metal molecular beam through the opening to deposit a metal film on the substrate, the metal molecular beam being irradiated at an incident angle .theta. within a range of 5 deg .ltoreq..theta..ltoreq.tan.sup.-1 (b/2a) deg ('a' and 'b' being the depth and diameter of the opening, respectively) relative to the normal of the substrate.

Growing community of inventors

Kawasaki, Japan

Ryoichi Mukai