Fuji Photo Film Company, Limited

Akira Nahara

Makoto Nagao

Yoshihiro Arai

Takashi Yamada

Masaaki Nomura

Ryoichi Yamamoto

Tomoaki Ikeda

Fusao Yamanaka

Yuzo Mizobuchi

Goro Akashi

Kunihiko Sano

Yoshihiro Ono

Tomizo Namiki

Satoshi Matsubaguchi

Kiyotaka Fukino

Fumiaki Shinozaki

Tatsuji Kitamoto

Shigeo Harada

Yasuo Washizawa

Takeshi Tomotsu

Satoshi Yoshida

Hiroyuki Iwasaki

Osamu Seshimoto

Ryuji Shirahata

Yasuo Nishikawa

Minoru Wada

Manabu Higuchi

Hiroshi Amari

A magnetic recording medium comprising a nonmagnetic substrate having thereon a magnetic layer, wherein the magnetic layer is a metal thin film comprising mainly a composition represented by the formula: (Co.sub.100-x Pd.sub.x).sub.100-y Cr.sub.y or [(Co..sub.100-x Pd.sub.x).sub.100-y Cr.sub.y ].sub.100-z O.sub.z wherein x, y and z are atomic percents, and 10.ltoreq.x 40, 5.ltoreq.y.ltoreq.25 and 0.5.ltoreq.z.ltoreq.15. The present medium can be produced at low costs, and has excellent perpendicular magnetic anisotropy.

Perpendicular magnetic recording medium comprising a magnetic thin film

A magneto-optical disk comprises a substrate and at least a magneto-optical recording layer provided on the substrate. A moisture barrier layer constituted of a fluorine resin is provided on the surface of the substrate on the side opposite to the substrate surface on which the magneto-optical recording layer is provided.

Magneto-optical disk

A magneto-optical recording medium has a substrate and a recording layer which is formed on the substrate. The recording layer is formed of a plurality of transition metal films and a plurality of rare earth metal films which are alternately formed one on the other, and at least a metal selected from the group consisting of Cr, Al and Ti is contained in the rare earth metal films or the transition metal films.

Magneto-optical recording medium and method of producing the same

A perpendicular magnetic recording medium such as a floppy disk is created by providing on at least one surface of a non-magnetic support, a magnetic layer having perpendicular magnetic anisotropy and a protective layer by sputtering. First, a magnetic layer is provided, secondly, the magnetic layer is surface treated by a plasma treatment or by applying an oxide layer or a nitride layer thereon and thirdly, the protective layer is applied thereto.

Perpendicular magnetic recording medium and the method for preparing the

A magneto-optical recording medium comprises a transparent substrate, a magneto-optical recording layer formed on the transparent substrate and containing a rare earth metal-transition metal alloy, and a thin film containing at least either one of platinum and palladium and formed at least on one surface of the magneto-optical recording layer. Or, the magneto-optical recording medium comprises the transparent substrate, and a magneto-optical recording layer formed on the transparent substrate by alternately overlaying a plurality of thin layers containing a rare earth metal-transition metal alloy, and a plurality of thin layers containing at least either one of platinum and palladium.

Magneto-optical recording medium with at least one protective layer

A method of making a magneto-optical recording medium comprises the step of forming a magneto-optical recording layer on a substrate by simultaneously carrying out direct current sputtering and radio-frequency sputtering. Alternatively, a magneto-optical recording layer composed of thin rare earth metal layers and thin transition metal layers overlaid alternately on a substrate is formed by carrying out radio-frequency sputtering by use of a target formed of a rare earth metal material and direct current sputtering by use of a target formed of a transition metal material.

Method of making magneto-optical recording medium

A magneto-optical recording medium comprises a recording layer formed of a magnetic material, and a protective layer composed of a combination of a dielectric material with a rare earth metal exhibiting a high oxygen absorptivity and formed on the recording layer by a simultaneous sputtering or a simultaneous deposition process, whereby free oxygen given rise to in the course of sputtering or deposition is absorbed on the protective layer side before being absorbed on the recording layer side.

Magneto-optical recording medium

A method of preparing a magnetic recording medium in which a magnetic layer is deposited on a non-magnetic support and then a carbon protective layer is sputtered onto the magnetic layer. The sputtering is performed with a bias voltage of -10V to -100V being applied in the vicinity of the support and magnetic layer.

Method for preparing a magnetic recording medium

Contaminant magnetic dust particles and flakes generated during the thin film coating of a substrate 9 in a vacuum chamber 1 are gravitationally collected in catch pans or troughs 8 disposed below the deposition zones. Magnets 10 are provided under the bottoms of the pans to enhance the attraction and retention of the particles. The contaminants may alternatively or additionally be removed directly from an upper surface of the substrate web by sandwiching one or more of its horizontal conveyance runs between a pair of magnets 22, 23, with the pole face area of the lower magnet being larger than that of the upper one.

Apparatus for producing magnetic recording medium

In a method of manufacturing a vertical magnetization type recording medium, a soft magnetic film layer is formed on each of the two sides of a non-magnetic support, and then a vertical magnetization film layer is formed on each soft magnetic film layer thus formed, thereby to provide a vertical magnetization type recording medium which has both sides uniform in characteristics and has characteristics making it excellent as a vertical magnetization type recording medium.

Vertical magnetization type recording medium and manufacturing method

Method of manufacturing vertical magnetization type recording medium

A magnetic recording medium is described, comprising a non-magnetic support having provided thereon a thin magnetic metal film and a protective layer mainly comprising carbon having a graphite structure containing at least one element selected from the group consisting of Mn, Mo, Nb, Ta, Ti, V, Cr and W.

Magnetic recording medium

A magneto-optical recording medium comprises a transparent substrate and a magneto-optical recording layer overlaid on the transparent substrate. The magneto-optical recording layer is formed by alternately overlaying a plurality of thin layers containing a rare earth metal-transition metal alloy for magneto-optical recording, and a plurality of thin layers containing at least one metal selected from the group consisting of gold, silver, lead, magnesium, copper, and iridium which are solid solution non-formable metals.

A magneto-optical recording medium comprises a substrate, a magneto-optical recording layer formed of a rare earth metal-transition metal alloy and a dielectric protective layer overlaid in this order on the substrate, and a rare earth metal layer overlaid on an edge face of the magneto-optical recording layer. The magneto-optical recording medium wherein the substrate is annular is made by forming the magneto-optical recording layer, covering the recording region on the magneto-optical recording layer with an annular mask having an outer diameter not larger than the outer diameter of the magneto-optical recording layer and/or an inner diameter not smaller than the inner diameter of the magneto-optical recording layer, overlaying the rare earth metal layer on an outer edge face and/or an inner edge face of the magneto-optical recording layer by dispersing rare earth metal particles toward the annular mask, removing the annular mask, and overlaying the dielectric protective layer on the magneto-optical recording layer.

Magneto-optical recording medium and method of making the same

An optical disk substrate has a surface on which a pre-groove for light beam tracking is formed. Non-pregrooved regions on the substrate surface on which the pregroove is formed are subjected to surface roughing processing to improve adhesion of the substrate surface in the non-pregrooved regions to a film which is to be overlaid on the optical disk substrate.

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Odawara, Japan

Akira Nahara