公开(公告)号：US20220246176A1

公开(公告)日：2022-08-04

申请号：US17649588

申请日：2022-02-01

申请人： SHOWA DENKO K.K.

发明人： Yoshitaka AONO ,  Takahiro UKAI ,  Takanao EBISAWA ,  Kazuya NIWA ,  Takayuki KONNO

IPC分类号： G11B5/667 ,  G11B5/851

摘要： 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.

公开(公告)号：US20190392863A1

公开(公告)日：2019-12-26

申请号：US16445772

申请日：2019-06-19

申请人： SHOWA DENKO K.K.

发明人： Takayuki FUKUSHIMA ,  Hisato SHIBATA ,  Yuji UMEMOTO ,  Kazuya NIWA ,  Lei ZHANG ,  Takehiro YAMAGUCHI ,  Chen XU ,  Tomoo SHIGE ,  Hiroshi KOYANAGI

IPC分类号： G11B5/65

摘要： 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：US20230131031A1

公开(公告)日：2023-04-27

申请号：US18146647

申请日：2022-12-27

申请人： SHOWA DENKO K.K.

发明人： Yoshitaka AONO ,  Takahiro UKAI ,  Takanao EBISAWA ,  Kazuya NIWA ,  Takayuki KONNO

IPC分类号： G11B5/667 ,  G11B5/851

摘要： 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.

公开(公告)号：US20200075053A1

公开(公告)日：2020-03-05

申请号：US16519157

申请日：2019-07-23

申请人： SHOWA DENKO K.K.

发明人： Takayuki FUKUSHIMA ,  Koji TAKE ,  Hisato SHIBATA ,  Takehiro YAMAGUCHI ,  Tomoo SHIGE ,  Lei ZHANG ,  Chen XU ,  Yuji UMEMOTO ,  Hiroshi KOYANAGI ,  Kazuya NIWA ,  Tetsuya KANBE

IPC分类号： G11B11/105 ,  G11B5/73 ,  G11B11/24

摘要： A heat-assisted magnetic recording medium includes a substrate, an underlayer, and a magnetic layer including an alloy having a L10 crystal structure and first and second layers, arranged in this order. Each of the first and second layers has a granular structure including C, SiO2, 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 SiO2 with respect to BN in each of the first and second layers is 0.25 to 3.5. Vol % of SiO2 in 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.

公开(公告)号：US20200005821A1

公开(公告)日：2020-01-02

申请号：US16445801

申请日：2019-06-19

申请人： SHOWA DENKO K.K.

发明人： Lei ZHANG ,  Takayuki FUKUSHIMA ,  Chen XU ,  Kazuya NIWA ,  Hisato SHIBATA ,  Takehiro YAMAGUCHI ,  Tetsuya KANBE ,  Tomoo SHIGE

IPC分类号： G11B5/65

摘要： 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：US20190180782A1

公开(公告)日：2019-06-13

申请号：US16169065

申请日：2018-10-24

申请人： SHOWA DENKO K.K.

发明人： Katsumi MUROFUSHI ,  Yoshitaka ISHIBASHI ,  Takayuki FUKUSHIMA ,  Kazuya NIWA ,  Lei ZHANG ,  Yuji MURAKAMI ,  Hisato SHIBATA ,  Takehiro YAMAGUCHI ,  Chen XU ,  Tetsuya KANBE ,  Tomoo SHIGE

IPC分类号： G11B5/851 ,  G11B5/65 ,  G11B5/72 ,  G11B5/82

摘要： 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：US20220358962A1

公开(公告)日：2022-11-10

申请号：US17658003

申请日：2022-04-05

申请人： SHOWA DENKO K.K.

发明人： Takayuki FUKUSHIMA ,  Tomoo SHIGE ,  Yuji UMEMOTO ,  Kazuya NIWA

IPC分类号： G11B5/65 ,  G11B5/127 ,  G11B5/012

摘要： A magnetic recording medium includes a substrate, and a magnetic recording layer including magnetic grains having an L10 structure. 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 (A111+A111e)/(A001+A111+A111e), is in a range of 0.2 to 0.7, where A111 denotes an area of the (111) plane, A111e denotes an area of the planes equivalent to the (111) plane, and A001 denotes an area of the (001) plane.

公开(公告)号：US20190392860A1

公开(公告)日：2019-12-26

申请号：US16433377

申请日：2019-06-06

申请人： SHOWA DENKO K.K.

发明人： Lei ZHANG ,  Chen XU ,  Takayuki FUKUSHIMA ,  Kazuya NIWA ,  Tetsuya KANBE ,  Hisato SHIBATA ,  Takehiro YAMAGUCHI ,  Tomoo SHIGE

IPC分类号： G11B5/31 ,  G11B5/48 ,  G11B5/65

摘要： 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

申请人： SHOWA DENKO K.K.

发明人： Kazuya NIWA ,  Tetsuya KANBE ,  Yuji MURAKAMI ,  Lei ZHANG ,  Hisato SHIBATA ,  Takayuki FUKUSHIMA ,  Satoru NAKAJIMA ,  Takehiro YAMAGUCHI

IPC分类号： G11B5/65 ,  G11B5/39 ,  G11B5/73 ,  G11B5/012 ,  G11B5/74 ,  G11B5/714 ,  G11B5/187

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

摘要： 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：US20180182421A1

公开(公告)日：2018-06-28

申请号：US15841930

申请日：2017-12-14

申请人： SHOWA DENKO K.K.

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

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

CPC分类号： G11B5/667 ,  G11B5/65 ,  G11B5/7325 ,  G11B5/851 ,  G11B11/10589

摘要： 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.