公开(公告)号：US11037591B2

公开(公告)日：2021-06-15

申请号：US16433377

申请日：2019-06-06

Applicant: SHOWA DENKO K.K.

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

IPC: G11B5/73 ,  G11B5/65 ,  G11B5/00

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

公开(公告)号：US11043238B1

公开(公告)日：2021-06-22

申请号：US17116223

申请日：2020-12-09

Applicant: SHOWA DENKO K.K.

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

IPC: G11B5/73 ,  G11B5/706

Abstract: 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 L10 structure.

公开(公告)号：US10706884B2

公开(公告)日：2020-07-07

申请号：US15850226

申请日：2017-12-21

Applicant: SHOWA DENKO K.K.

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

IPC: G11B5/73 ,  G11B5/65 ,  C22C19/07 ,  C22C27/06

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 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.

公开(公告)号：US10685674B2

公开(公告)日：2020-06-16

申请号：US16445772

申请日：2019-06-19

Applicant: SHOWA DENKO K.K.

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

IPC: G11B5/56 ,  G11B5/65 ,  G11B5/00

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

公开(公告)号：US10360936B2

公开(公告)日：2019-07-23

申请号：US15885013

申请日：2018-01-31

Applicant: SHOWA DENKO K.K.

Inventor： Kazuya Niwa ,  Tetsuya Kanbe ,  Yuji Murakami ,  Lei Zhang ,  Hisato Shibata ,  Takayuki Fukushima ,  Satoru Nakajima ,  Takehiro Yamaguchi

IPC: G11B5/65 ,  G11B5/738 ,  G11B5/39 ,  G11B5/73 ,  G11B5/187 ,  G11B5/74 ,  G11B5/714 ,  G11B5/012 ,  G11B5/31 ,  G11B5/00

Abstract: 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 L10-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.

公开(公告)号：US10127939B2

公开(公告)日：2018-11-13

申请号：US15868239

申请日：2018-01-11

Applicant: SHOWA DENKO K.K.

Inventor： Kazuya Niwa ,  Lei Zhang ,  Yuji Murakami ,  Hisato Shibata ,  Takayuki Fukushima ,  Takehiro Yamaguchi ,  Tetsuya Kanbe

IPC: G11B5/68 ,  G11B5/65 ,  G11B5/48 ,  G11B5/706 ,  G11B5/667 ,  G11B5/73 ,  G11B5/00

Abstract: 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 L10 crystal 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.