Showa Denko K.k.

Tohoku University

Resonac Corporation

Resonac Hard Disk Corporation

Kazuya Niwa

Lei Zhang

Tetsuya Kanbe

Takayuki Fukushima

Yuji Murakami

Hisato Shibata

Takehiro Yamaguchi

Tomoo Shige

Chen Xu

Yuji Umemoto

Hiroshi Koyanagi

Shin Saito

Takahiro Ukai

Takanao Ebisawa

Yoshitaka Aono

Takayuki Konno

Hiroaki Nemoto

Katsumi Murofushi

Atsushi Hashimoto

Ryuji Sakaguchi

Haruhisa Ohashi

Yoshitaka Ishibashi

Shintaro Hinata

Koji Take

Satoru Nakajima

Katsuya Hara

A method of manufacturing a magnetic recording medium including: forming a diffusion preventing layer, wherein the magnetic recording medium includes a non-magnetic substrate; an underlayer; a perpendicular magnetic layer; the diffusion preventing layer; and a protective layer, wherein the perpendicular magnetic layer has a multi-layer structure, the perpendicular magnetic layer includes an uppermost layer and at least one layer other than the uppermost layer, the uppermost layer including Co or Fe in magnetic particles, and the at least one layer other than the uppermost layer including an oxide, the diffusion preventing layer is provided between the perpendicular magnetic layer and the protective layer, and the diffusion preventing layer includes at least one component selected from a group consisting of Si, Ti, Cr, B, and Ru, or either a carbide, an oxide, or both, of the at least one component.

Method of manufacturing magnetic recording medium

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 including: a non-magnetic substrate; an underlayer; a perpendicular magnetic layer; a diffusion preventing layer; and a protective layer, wherein the underlayer, the perpendicular magnetic layer, the diffusion preventing layer, and the protective layer are layered on the non-magnetic substrate in this order, the perpendicular magnetic layer has a multi-layer structure, the perpendicular magnetic layer includes an uppermost layer and at least one layer other than the uppermost layer, the uppermost layer including Co or Fe in magnetic particles, and the at least one layer other than the uppermost layer including an oxide, the diffusion preventing layer is provided between the perpendicular magnetic layer and the protective layer, and the diffusion preventing layer includes at least one component selected from a group consisting of Si, Ti, Cr, B, and Ru, or either a carbide, an oxide, or both, of the at least one component.

Magnetic recording medium, magnetic recording and reproducing apparatus, and method of manufacturing magnetic recording medium

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.

The invention provides a magnetic recording medium with an excellent signal-to-noise ratio during reading by reducing the noise produced during writing of data onto the magnetic recording medium, and increasing the signal level. The assisted magnetic recording medium according to one embodiment comprising a substrate, a base layer, and a magnetic layer composed mainly of an alloy with an L1-type crystal structure, the assisted magnetic recording medium having a pinning layer in contact with the magnetic layer, and the pinning layer including Co or an alloy composed mainly of Co.

Assisted magnetic recording medium including a pinning layer and magnetic storage device

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.

A magnetic recording medium includes a substrate, a first heat sink layer, a barrier layer, a second heat sink layer, and a magnetic layer that are successively stacked. The magnetic layer is made of a material including a first main component that is an alloy having a L1crystal structure and a content of 50 at % or higher, or content of 50 mol % or higher. The barrier layer is made of a material including a second main component that is one of an oxide, a nitride, and a carbide having a content of 50 at % or higher, or content of 50 mol % or higher.

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Chiba, Japan

Kazuya Niwa