Showa Denko K.k.

Resonac Corporation

Tohoku University

Lei Zhang

Tetsuya Kanbe

Kazuya Niwa

Takayuki Fukushima

Hisato Shibata

Takehiro Yamaguchi

Yuji Murakami

Chen Xu

Tomoo Shige

Yuji Umemoto

Hiroshi Koyanagi

Haruhisa Ohashi

Shin Saito

Hiroaki Nemoto

Katsumi Murofushi

Atsushi Hashimoto

Yoshitaka Ishibashi

Shintaro Hinata

Koji Take

Satoru Nakajima

Koichi Nagasaka

Fumito Kudo

Yuki Hirai

Kensuke Yamanaka

Masayuki Makita

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 property measuring apparatus measures magnetic properties of a magnetic recording medium, and includes a rotating mechanism which rotates the magnetic recording medium, a heating or cooling mechanism which heats or cools the magnetic recording medium; a temperature measuring mechanism which measures a temperature of the magnetic recording medium, a laser heating mechanism, disposed opposite to a measurement site of the magnetic recording medium, which heats the measurement site without making contact with the measurement site, a magnetic write part, disposed opposite to the measurement site, which magnetizes the measurement site without making contact with the measurement site, and a magnetic read part, disposed opposite to the measurement site, which reads a magnetic flux leakage at the measurement site without making contact with the measurement site.

Magnetic property measuring apparatus and magnetic property measuring method

The present invention relates to a magnetic recording medium including a substrate; an underlayer laminated upon the substrate; and a magnetic layer laminated upon the underlayer, wherein the underlayer includes a first underlayer containing a compound represented by a following general formula: MgO, where X is within a range of 0.07 to 0.25, the magnetic layer includes a first magnetic layer containing an alloy having a L1structure, and the alloy having the L1structure includes B, and the first underlayer is in contact with the first magnetic layer.

Magnetic recording medium, method of manufacturing magnetic recording medium and magnetic storage device

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 magnetic recording medium includes a substrate, an underlayer provided above the substrate, and a magnetic layer provided on and in contact with the underlayer. The underlayer includes a compound represented by a general formula MgO, where x falls within a range of 0.07 to 0.25. The magnetic layer includes an alloy having a L1structure, and the alloy having the L1structure includes one or more elements selected from a group consisting of Al, Si, Ga, and Ge.

Magnetic recording medium utilizing adjacent underlayer and magnetic layer having particular compositions, magnetic storage apparatus, and method of manufacturing magnetic recording medium

A magnetic recording medium includes a substrate; a soft magnetic underlayer laminated on the substrate; an amorphous barrier layer laminated on the soft magnetic underlayer; and a magnetic recording layer laminated on the amorphous barrier layer, wherein the soft magnetic underlayer includes Fe, B, Si, and one or more elements selected from the group consisting of Nb, Zr, Mo, and Ta, wherein the amorphous barrier layer includes Si, W, and one or more elements selected from the group consisting of Nb, Zr, Mo, and Ta, and wherein the magnetic recording layer includes an alloy having an L1structure.

Magnetic recording medium and magnetic storage device

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; a first underlayer; a second underlayer; and a magnetic layer including an alloy having a L1type crystal structure with a (001) orientation. The substrate, the first underlayer, the second underlayer, and the magnetic layer are stacked in this order. The first underlayer is a crystalline layer that includes Mo as a main component. The second underlayer is a crystalline layer that includes a material containing Mo as a main component and that includes an oxide. The content of the oxide in the second underlayer is in a range of from 2 mol % to 30 mol %. The oxide is an oxide of one or more kinds of elements selected from a group consisting of Cr, Mo, Nb, Ta, V, and W.

A magnetic recording medium includes: a substrate; a first underlayer; a second underlayer; and a magnetic layer including an alloy having a L1type crystal structure with a (001) orientation. The substrate, the first underlayer the second underlayer, and the magnetic layer are stacked in this order. The first underlayer is a crystalline layer that includes W as a main component. The second underlayer is a crystalline layer that includes a material containing W as a main component and that includes an oxide. The content of the oxide in the second underlayer is in a range of from 2 mol % to 30 mol %. The oxide is an oxide of one or more kinds of elements selected from a group consisting of Cr, Mo, Nb, Ta, V, and W.

A magnetic recording medium includes: a substrate; an underlayer; and a magnetic layer including an alloy having a L1type crystal structure whose plane orientation is (001). The substrate, the underlayer, and the magnetic layer are stacked in this order. The underlayer includes a first underlayer. The first underlayer is a crystalline layer that includes a material containing Al, Ag, Cu, W, or Mo as a main component element and includes an oxide of the main component element, a content of the oxide of the main component element in the first underlayer being in a range of from 2 mol % to 30 mol %.

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.

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Chiba, Japan

Lei Zhang