Showa Denko K.k.

Tohoku University

Resonac Corporation

Waseda University

Tomoo Shige

Kazuya Niwa

Takayuki Fukushima

Lei Zhang

Hisato Shibata

Takehiro Yamaguchi

Chen Xu

Tetsuya Kanbe

Yuji Umemoto

Hiroshi Koyanagi

Akira Sakawaki

Yuji Murakami

Shin Saito

Akira Yamane

Hiroaki Nemoto

Masato Fukushima

Katsumi Murofushi

Tetsuya Osaka

Atsushi Hashimoto

Yoshitaka Ishibashi

Haruhisa Ohashi

Shintaro Hinata

Atsushi Sugiyama

Yoshiko Takahashi

Koji Take

Takuma Hachisu

Makoto Hiwatari

Yuki Hirai

A magnetic recording medium includes a substrate, an underlayer formed on the substrate, and a magnetic layer formed on the underlayer. The magnetic layer includes an alloy having a L1structure. The underlayer includes a first underlayer and a second underlayer. The first underlayer includes Mo and Ru, the content of Ru in the first underlayer is in a range of 5 atom % to 30 atom %, and the second underlayer includes a material having a body-centered cubic (BCC) structure. The second underlayer is formed between the first underlayer and the substrate.

Magnetic recording medium and magnetic read/write apparatus

A magnetic recording medium includes a substrate, and a magnetic recording layer including magnetic grains having an L1structure. The magnetic recording layer is (001) oriented, and a surface of growth of the magnetic recording layer includes a (001) plane, a (111) plane, and planes equivalent to the (111) plane. An area ratio of the (111) plane and the planes equivalent to the (111) plane, represented by (A+A)/(A+A+A), is in a range of 0.2 to 0.7, where Adenotes an area of the (111) plane, Adenotes an area of the planes equivalent to the (111) plane, and Adenotes an area of the (001) plane.

Magnetic recording medium, magnetic storage apparatus, and method for manufacturing magnetic recording medium

A magnetic recording medium includes a substrate, an underlayer provided on the substrate, and a magnetic layer provided on the underlayer and having a L1structure and a (001) orientation. The magnetic layer has a granular structure in which an organic compound having a methylene skeleton or a methine skeleton is arranged at grain boundaries of magnetic grains.

Magnetic recording medium, sputtering target, sputtering target manufacturing method, and magnetic storage apparatus

A heat-assisted magnetic recording medium includes: a substrate; an underlayer; and a magnetic layer including an alloy having an L1structure, wherein the underlayer includes, from the substrate side, a bcc underlayer including a substance having a bcc structure, a first oxide layer that is in contact with the bcc underlayer, and a second oxide layer that is in contact with the magnetic layer. The bcc underlayer, the first oxide layer, and the second oxide layer are stacked in the recited order. The first oxide layer and the second oxide layer include magnesium oxide, and the second oxide layer further includes one or more compounds selected from the group consisting of vanadium oxide, vanadium nitride, and vanadium carbide.

Heat-assisted magnetic recording medium and magnetic storage apparatus

A magnetic recording medium includes a substrate, an underlayer, and a magnetic layer that are arranged in this order. The magnetic layer has a granular structure including magnetic grains having a L1crystal structure, and grain boundary parts having a volume fraction in a range of 25 volume % to 50 volume %. The magnetic grains have a c-axis orientation with respect to the substrate. The grain boundary parts include a material having a lattice constant in a range of 0.30 nm to 0.36 nm, or in a range of 0.60 nm to 0.72 nm.

High density magnetic recording medium for heat-assisted magnetic storage apparatus

A magnetic recording medium includes: a substrate; an underlayer; and a magnetic layer including an alloy having a L1structure and a (001) orientation, wherein the substrate, the underlayer, and the magnetic layer are stacked in the recited order, and wherein the magnetic layer has a granular structure and includes a carbon hydride, a boron hydride, or a boron nitride hydride.

Magnetic recording medium and magnetic storage apparatus

A magnetic recording medium includes: a substrate; an underlayer; a magnetic layer including an alloy having an L1type crystal structure; and a protective layer, wherein the substrate, the underlayer, the magnetic layer, and the protective layer are stacked in the recited order. A pinning layer is further included between the magnetic layer and the protective layer, and the pinning layer includes a magnetic material including Co and includes at least one metal selected from the group consisting of Cu, Ag, Au, and Al.

Assisted magnetic recording medium and magnetic storage apparatus

A heat-assisted magnetic recording medium includes: a substrate; an underlayer; and a magnetic layer including an alloy having an L1structure. The substrate, the underlayer, and the magnetic layer are stacked in the recited order. The underlayer includes a first underlayer. The first underlayer includes magnesium oxide and one or more compounds selected from the group consisting of vanadium oxide, zinc oxide, tin oxide, vanadium nitride, and vanadium carbide, and a total content of the one or more compounds is in a range of 45 mol % to 70 mol %.

A heat-assisted magnetic recording medium includes a substrate, an underlayer, and a magnetic layer including an alloy having a L1crystal structure and first and second layers, arranged in this order. Each of the first and second layers has a granular structure including C, SiO, and BN at grain boundaries. Vol % of the grain boundaries in each of the first and second layers is 25 to 45 vol %. Vol % of C in the first layer is 5 to 22 vol %, and a volume ratio of SiOwith respect to BN in each of the first and second layers is 0.25 to 3.5. Vol % of SiOin the second layer is greater than that of the first layer by 5 vol % or more. Vol % of BN in the second layer is smaller than that in the first layer by 2 vol % or more.

A heat-assisted magnetic recording medium includes: a substrate; an underlayer; and a magnetic layer that is (001)-oriented. In the magnetic layer, a first magnetic layer and a second magnetic layer are stacked in this order from the underlayer side. The first magnetic layer and the second magnetic layer include an alloy having an L1structure. The second magnetic layer includes a ferrite at grain boundaries of magnetic grains. The ferrite is one or more kinds selected from the group consisting of NiFeO, MgFeO, MnFeO, CuFeO, ZnFeO, CoFeO, BaFeO, SrFeO, and FeO. A Curie temperature of the magnetic grains is lower than a Curie temperature of the ferrite.

A magnetic recording medium includes a substrate, a barrier layer, a crystal grain size control layer, and a magnetic layer that are arranged in this order. The barrier layer includes at least one of oxides, nitrides, and carbides, and the crystal grain size control layer is a crystalline layer including Ag and having an average thickness in a range of 0.1 nm to 1 nm. The barrier layer makes contact with the crystal grain size control layer, and the magnetic layer includes an alloy having a L1crystal structure and a (001) face orientation.

According to the present invention, a magnetic recording medium is provided including a disk-shaped non-magnetic substrate and at least a perpendicular magnetic layer formed on the disk-shaped non-magnetic substrate, wherein the perpendicular magnetic layer has a structure in which an FePt or CoPt nanoparticle array is formed on a formation surface, on which a plurality of striations each having a circumferential directional component are formed, by a texturing treatment; a manufacturing method thereof; and a magnetic record/reproduction apparatus including the magnetic recording medium or a magnetic recording medium manufactured according to the manufacturing method.

Magnetic recording medium and method of manufacturing the same, and magnetic record/reproduction apparatus

A method of manufacturing a magnetic recording medium is provided. The method includes: forming a magnetic layeron a non-magnetic substrate; forming a mask layeron the magnetic layer; forming a resist layerwhich is patterned into a predetermined shape on the mask layer; patterning the mask layerinto a shape corresponding to the resist layerusing the resist layer; patterning the magnetic layerinto a shape corresponding to the mask layerusing the patterned mask layer; and removing the mask layerthat remains on the magnetic layerby reactive plasma etching. The reactive plasma etching is performed under an atmosphere containing an organic compound having at least one kind or plural kinds of functional groups selected from a hydroxyl group, a carbonyl group, a hydroxy carbonyl group, an alkoxy group, and an ether group.

Method of manufacturing magnetic recording medium, and magnetic recording and reproducing device

A method of manufacturing a magnetic recording medium is provided, which include: forming a magnetic layer on the surface of a nonmagnetic substrate; forming a groove in which a nonmagnetic section is formed by etching a portion corresponding to a formation region of the nonmagnetic section in the magnetic layer and a magnetic recording section formed of the magnetic layer; applying a resin having an active energy ray curable functional group to the surface of the magnetic recording section so as to fill the groove; pressing a plate material against the resin so that the smooth surface of the plate material is in contact with the surface of the resin to make the surface of the resin smooth; removing the plate material from the resin; and forming the nonmagnetic section in the groove by etching and removing a portion located above the surface of the magnetic recording section in the resin having a smooth surface.

Growing community of inventors

Chiba, Japan

Tomoo Shige