公开(公告)号：US11244700B2

公开(公告)日：2022-02-08

申请号：US16169065

申请日：2018-10-24

Applicant: SHOWA DENKO K.K.

Inventor： Katsumi Murofushi ,  Yoshitaka Ishibashi ,  Takayuki Fukushima ,  Kazuya Niwa ,  Lei Zhang ,  Yuji Murakami ,  Hisato Shibata ,  Takehiro Yamaguchi ,  Chen Xu ,  Tetsuya Kanbe ,  Tomoo Shige

IPC: G11B5/65 ,  G11B5/72 ,  G11B5/82 ,  G11B5/851 ,  C08L61/28

Abstract: A magnetic recording medium includes a substrate, an underlayer provided on the substrate, and a magnetic layer provided on the underlayer and having a L10 structure 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.

公开(公告)号：US12087341B2

公开(公告)日：2024-09-10

申请号：US16862809

申请日：2020-04-30

Applicant: SHOWA DENKO K.K.

Inventor： Chen Xu ,  Lei Zhang ,  Takayuki Fukushima ,  Hisato Shibata ,  Takehiro Yamaguchi ,  Kazuya Niwa ,  Tomoo Shige ,  Hiroaki Nemoto ,  Yuji Umemoto ,  Hiroshi Koyanagi

IPC: G11B5/66 ,  G11B5/65 ,  G11B5/73

CPC classification number: G11B5/73919 ,  G11B5/657 ,  G11B5/658

Abstract: 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 L10 structure. 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.

公开(公告)号：US10978103B2

公开(公告)日：2021-04-13

申请号：US16407412

申请日：2019-05-09

Applicant: SHOWA DENKO K.K.

Inventor： Takayuki Fukushima ,  Kazuya Niwa ,  Lei Zhang ,  Hisato Shibata ,  Takehiro Yamaguchi ,  Chen Xu ,  Tetsuya Kanbe ,  Tomoo Shige

IPC: G11B5/66 ,  G11B5/64 ,  G11B5/65

Abstract: A magnetic recording medium includes: a substrate; an underlayer; and a magnetic layer including an alloy having a L10 structure 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.

公开(公告)号：US10699737B2

公开(公告)日：2020-06-30

申请号：US15859989

申请日：2018-01-02

Applicant: SHOWA DENKO K.K.

Inventor： Takayuki Fukushima ,  Haruhisa Ohashi ,  Lei Zhang ,  Yuji Murakami ,  Hisato Shibata ,  Takehiro Yamaguchi ,  Tetsuya Kanbe

IPC: G11B5/66 ,  G11B5/65 ,  G11B5/73 ,  G11B5/00

Abstract: A magnetic recording medium includes: a substrate; an underlayer; and a magnetic layer including an alloy having a L10 type 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 %.

公开(公告)号：US10553242B2

公开(公告)日：2020-02-04

申请号：US16445801

申请日：2019-06-19

Applicant: SHOWA DENKO K.K.

Inventor： Lei Zhang ,  Takayuki Fukushima ,  Chen Xu ,  Kazuya Niwa ,  Hisato Shibata ,  Takehiro Yamaguchi ,  Tetsuya Kanbe ,  Tomoo Shige

IPC: G11B5/65 ,  G11B5/00

Abstract: 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 L10 structure. 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 NiFe2O4, MgFe2O4, MnFe2O4, CuFe2O4, ZnFe2O3, CoFe2O4, BaFe2O4, SrFe2O4, and Fe3O4. A Curie temperature of the magnetic grains is lower than a Curie temperature of the ferrite.

公开(公告)号：US11024334B2

公开(公告)日：2021-06-01

申请号：US16835770

申请日：2020-03-31

Applicant: SHOWA DENKO K.K.

Inventor： Takayuki Fukushima ,  Chen Xu ,  Lei Zhang ,  Hisato Shibata ,  Takehiro Yamaguchi ,  Kazuya Niwa ,  Tomoo Shige ,  Hiroaki Nemoto ,  Yuji Umemoto ,  Hiroshi Koyanagi

IPC: G11B11/105 ,  G11B5/65 ,  G11B5/66 ,  G11B5/60 ,  G11B5/00

Abstract: 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 L10 crystal 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.

公开(公告)号：US10803895B2

公开(公告)日：2020-10-13

申请号：US15859973

申请日：2018-01-02

Applicant: SHOWA DENKO K.K.

Inventor： Takayuki Fukushima ,  Haruhisa Ohashi ,  Lei Zhang ,  Yuji Murakami ,  Hisato Shibata ,  Takehiro Yamaguchi ,  Tetsuya Kanbe

IPC: G11B5/65 ,  G11B5/73 ,  G11B5/00

Abstract: A magnetic recording medium includes: a substrate; a first underlayer; a second underlayer; and a magnetic layer including an alloy having a L10 type 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.

公开(公告)号：US10283154B2

公开(公告)日：2019-05-07

申请号：US15979965

申请日：2018-05-15

Applicant: SHOWA DENKO K.K. ,  TOHOKU UNIVERSITY

Inventor： Shintaro Hinata ,  Shin Saito ,  Takayuki Fukushima ,  Haruhisa Ohashi ,  Kazuya Niwa ,  Lei Zhang ,  Yuji Murakami ,  Hisato Shibata ,  Takehiro Yamaguchi ,  Tetsuya Kanbe ,  Tomoo Shige

IPC: G11B5/65 ,  G11B5/66 ,  G11B5/48 ,  G11B5/73 ,  G11B5/00 ,  G11B5/60

Abstract: 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 L10 crystal structure and a (001) face orientation.

公开(公告)号：US11676632B2

公开(公告)日：2023-06-13

申请号：US17104504

申请日：2020-11-25

Applicant: SHOWA DENKO K.K.

Inventor： Takayuki Fukushima ,  Lei Zhang ,  Chen Xu ,  Hisato Shibata ,  Takehiro Yamaguchi ,  Hiroshi Koyanagi ,  Yuji Umemoto

IPC: G11B5/73 ,  G11B5/851 ,  C23C14/08 ,  C23C14/34 ,  C23C14/00 ,  G11B5/716 ,  C23C14/35

CPC classification number: G11B5/736 ,  C23C14/0057 ,  C23C14/081 ,  C23C14/34 ,  C23C14/35 ,  G11B5/716 ,  G11B5/7369 ,  G11B5/851 ,  Y10T428/115

Abstract: 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(1-X), 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 L10 structure, and the alloy having the L10 structure includes B, and the first underlayer is in contact with the first magnetic layer.

公开(公告)号：US11189313B2

公开(公告)日：2021-11-30

申请号：US17141367

申请日：2021-01-05

Applicant: SHOWA DENKO K.K.

Inventor： Koichi Nagasaka ,  Takayuki Fukushima ,  Lei Zhang ,  Chen Xu ,  Hisato Shibata ,  Takehiro Yamaguchi ,  Hiroshi Koyanagi ,  Yuji Umemoto

IPC: G11B5/70 ,  G11B5/706 ,  G11B5/73 ,  G11B5/33 ,  G11B5/851 ,  G11B5/716 ,  G11B5/66

Abstract: 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(1-x), where x falls within a range of 0.07 to 0.25. The magnetic layer includes an alloy having a L10 structure, and the alloy having the L10 structure includes one or more elements selected from a group consisting of Al, Si, Ga, and Ge.