公开(公告)号：US20200005823A1

公开(公告)日：2020-01-02

申请号：US16448187

申请日：2019-06-21

Applicant: SHOWA DENKO K.K. ,  TOHOKU UNIVERSITY

Inventor： Shin SAITO ,  Takayuki FUKUSHIMA ,  Lei ZHANG ,  Hisato SHIBATA ,  Takehiro YAMAGUCHI ,  Chen XU ,  Tetsuya KANBE ,  Tomoo SHIGE ,  Kazuya NIWA ,  Atsushi HASHIMOTO

IPC: G11B5/73

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

公开(公告)号：US20190355387A1

公开(公告)日：2019-11-21

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

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：US20180358041A1

公开(公告)日：2018-12-13

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 ,  G11B5/48 ,  G11B5/66

CPC classification number: G11B5/65 ,  G11B5/4866 ,  G11B5/66 ,  G11B2005/0021

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：US20170365279A1

公开(公告)日：2017-12-21

申请号：US15596109

申请日：2017-05-16

Applicant: SHOWA DENKO K.K.

Inventor： Takayuki FUKUSHIMA ,  Yuji MURAKAMI ,  Tetsuya KANBE ,  Lei ZHANG ,  Kazuya NIWA ,  Hisato SHIBATA

IPC: G11B5/187 ,  G11B5/706 ,  G11B5/39 ,  G11B5/66 ,  G11B5/84 ,  G11B5/73

CPC classification number: G11B5/1875 ,  G11B5/398 ,  G11B5/65 ,  G11B5/66 ,  G11B5/706 ,  G11B5/70615 ,  G11B5/716 ,  G11B5/73 ,  G11B5/743 ,  G11B5/8404 ,  G11B5/855

Abstract: A magnetic recording medium includes a substrate; a lower base layer formed on the substrate; and a (001) oriented L10 magnetic layer formed on the lower base layer and including a first magnetic layer formed on the lower base layer and having a granular structure of magnetic grains and a grain boundary portion, the grain boundary portion containing C, and a second magnetic layer formed on the first magnetic layer and having a granular structure of magnetic grains and a grain boundary portion, the grain boundary portion containing oxide or nitride, the second magnetic layer further containing one or more elements selected from a group consisting of Mg, Ni, Zn, Ge, Pd, Sn, Ag, Re, Au and Pb as an additive.

公开(公告)号：US20210201947A1

公开(公告)日：2021-07-01

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: G11B5/851 ,  G11B5/73 ,  C23C14/08 ,  C23C14/35

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：US20190392860A1

公开(公告)日：2019-12-26

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: G11B5/31 ,  G11B5/48 ,  G11B5/65

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：US20180261245A1

公开(公告)日：2018-09-13

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 ,  G11B5/39 ,  G11B5/73 ,  G11B5/012 ,  G11B5/74 ,  G11B5/714 ,  G11B5/187

CPC classification number: G11B5/656 ,  G11B5/012 ,  G11B5/1875 ,  G11B5/3133 ,  G11B5/3912 ,  G11B5/714 ,  G11B5/73 ,  G11B5/7325 ,  G11B5/746 ,  G11B2005/0021

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：US20180211688A1

公开(公告)日：2018-07-26

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

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：US20180204591A1

公开(公告)日：2018-07-19

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: G11B5/70 ,  G11B5/65

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：US20180182421A1

公开(公告)日：2018-06-28

申请号：US15841930

申请日：2017-12-14

Applicant: SHOWA DENKO K.K.

Inventor： Takayuki FUKUSHIMA ,  Kazuya NIWA ,  Lei ZHANG ,  Yuji MURAKAMI ,  Hisato SHIBATA ,  Takehiro YAMAGUCHI ,  Tetsuya KANBE

IPC: G11B5/667 ,  G11B11/105 ,  G11B5/65 ,  G11B5/73

CPC classification number: G11B5/667 ,  G11B5/65 ,  G11B5/7325 ,  G11B5/851 ,  G11B11/10589

Abstract: A magnetic recording medium includes a substrate, an underlayer, and a magnetic layer including an alloy having a L10 type crystal structure with a (001) orientation, wherein 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 W as a main component and a nitride whose content ranges from 1 mol % to 80 mol %, and the nitride includes one or more elements selected from a group consisting of Al, B, Si, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, and W.