公开(公告)号：US20210201944A1

公开(公告)日：2021-07-01

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: G11B5/706

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：US20190392863A1

公开(公告)日：2019-12-26

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: G11B5/65

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：US20160351223A1

公开(公告)日：2016-12-01

申请号：US15088341

申请日：2016-04-01

Applicant: SHOWA DENKO K.K.

Inventor： Chen XU ,  Gohei KUROKAWA

IPC: G11B5/667 ,  G11B5/65 ,  G11B5/127

CPC classification number: G11B5/1278 ,  G11B5/7325

Abstract: A perpendicular magnetic recording medium includes a soft magnetic underlayer, an underlayer, an intermediate layer, and a perpendicular magnetic recording layer successively stacked on a nonmagnetic substrate. The soft magnetic underlayer includes a soft magnetic layer having an amorphous structure. The underlayer includes a first underlayer, and a second underlayer provided between the first underlayer and the intermediate layer. The first underlayer is made of a TiV alloy having an amorphous structure, and the second underlayer is made of an NiW alloy including at least one element selected from a group consisting of Co, Cu, Al, Cr, and Fe. The intermediate layer is made of Ru or an Ru alloy, and wherein the soft magnetic layer, the first underlayer, and the second underlayer are stacked in this order.

Abstract translation: 垂直磁记录介质包括依次层叠在非磁性基板上的软磁性底层，底层，中间层和垂直磁记录层。 软磁性底层包括具有非晶结构的软磁性层。 底层包括第一底层和设置在第一底层和中间层之间的第二底层。 第一底层由具有非晶结构的TiV合金制成，第二底层由包括选自Co，Cu，Al，Cr和Fe中的至少一种元素的NiW合金制成。 中间层由Ru或Ru合金制成，其中软磁层，第一底层和第二底层按此顺序堆叠。

公开(公告)号：US20220319546A1

公开(公告)日：2022-10-06

申请号：US17656964

申请日：2022-03-29

Applicant: SHOWA DENKO K.K. ,  TOHOKU UNIVERSITY

Inventor： Chen XU ,  Gohei KUROKAWA ,  Lei ZHANG ,  Takayuki FUKUSHIMA ,  Tomoo SHIGE ,  Shin SAITO

IPC: G11B5/66 ,  G11B5/851

Abstract: A magnetic recording medium includes a magnesium oxide underlayer including magnesium oxide, and a magnetic layer including an alloy having a L10 structure and includes Fe or Co and Pt. The magnesium oxide has a peak of an O1s spectrum detected in a range of 531 eV to 533 eV when measured by X-ray photoelectron spectroscopy.

公开(公告)号：US20210256998A1

公开(公告)日：2021-08-19

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: G11B5/73 ,  G11B5/851 ,  G11B5/33

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.

公开(公告)号：US20160300591A1

公开(公告)日：2016-10-13

申请号：US15096351

申请日：2016-04-12

Applicant: SHOWA DENKO K.K.

Inventor： Chen XU ,  Gohei KUROKAWA

IPC: G11B5/73 ,  G11B5/738 ,  G11B5/127

CPC classification number: G11B5/1278 ,  G11B5/667 ,  G11B5/732 ,  G11B5/7325

Abstract: A perpendicular magnetic recording medium includes a structure in which at least a soft magnetic backing layer, an underlayer, an intermediate layer, and a perpendicular magnetic recording layer are sequentially laminated on a non-magnetic substrate, in which the soft magnetic backing layer includes at least a soft magnetic film having an amorphous structure, the underlayer includes a first underlayer and a second underlayer laminated in this order from the non-magnetic substrate side, the first underlayer is made of a TiV alloy having an amorphous structure, the second underlayer includes a NiW alloy, the intermediate layer includes Ru or a Ru alloy, the soft magnetic film having an amorphous structure directly contacts the first underlayer, and the first underlayer directly contacts the second underlayer.

Abstract translation: 垂直磁记录介质包括其中至少软磁背衬层，底层，中间层和垂直磁记录层依次层压在非磁性基板上的结构，其中软磁背衬层包括在 至少具有非晶结构的软磁性膜，所述底层包括从非磁性基板一侧依次层叠的第一底层和第二下层，所述第一底层由具有非晶结构的TiV合金制成，所述第二底层包括 NiW合金，中间层包括Ru或Ru合金，具有非晶结构的软磁膜直接接触第一底层，第一底层直接接触第二底层。

公开(公告)号：US20200327905A1

公开(公告)日：2020-10-15

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: G11B5/65 ,  G11B5/66 ,  G11B5/60

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：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：US20220310119A1

公开(公告)日：2022-09-29

申请号：US17650119

申请日：2022-02-07

Applicant: SHOWA DENKO K.K.

Inventor： Takehiro YAMAGUCHI ,  Hisato SHIBATA ,  Takayuki FUKUSHIMA ,  Chen XU

IPC: G11B5/73 ,  G11B5/012

Abstract: A magnetic recording medium includes a substrate, an underlayer provided on the substrate and including MgO, and a magnetic layer provided on the underlayer and including an alloy having a L10 crystal structure. The magnetic layer includes first, second, and third magnetic recording layers successively provided in this order above the underlayer. A Curie temperature of the second magnetic recording layer is lower than a Curie temperature of each of the first and third magnetic recording layers, by a value which falls within a range of 30 K to 100 K. An average grain diameter of magnetic grains at a bottom surface portion of the first magnetic recording layer is smaller by 15% or more than average grain diameters of magnetic grains at bottom surface portions of the second and third magnetic recording layers.