公开(公告)号：US07368185B2

公开(公告)日：2008-05-06

申请号：US10977552

申请日：2004-10-29

Applicant: Yoshiyuki Hirayama ,  Yuzuru Hosoe ,  Hiroyuki Nakagawa ,  Ikuko Takekuma

Inventor： Yoshiyuki Hirayama ,  Yuzuru Hosoe ,  Hiroyuki Nakagawa ,  Ikuko Takekuma

IPC: G11B5/66 ,  G11B5/70

CPC classification number: G11B5/7325 ,  G11B5/65 ,  G11B5/656

Abstract: Embodiments of the invention provide a perpendicular magnetic recording medium that not only attains the magnetic isolation of crystal grains in a magnetic recording layer from one another in a region of the medium in which the thickness of an intermediate layer is equal to or smaller than about 20 nm but also exhibits excellent crystallographic texture and that exhibits small medium noise, excellent thermal stability, and high write-ability. In one embodiment, a perpendicular magnetic recording medium has at least a soft-magnetic underlayer, a first intermediate layer, a second intermediate layer, a third intermediate layer, and a magnetic recording layer successively formed on a substrate. The magnetic recording layer is composed of ferromagnetic crystal grains and oxides or nitrides, the third intermediate layer is composed of Ru or an Ru alloy, the second intermediate layer is composed of a metal or an alloy having the face-centered cubic lattice structure, and the first intermediate layer is composed of a metal or an alloy having the hexagonal close-packed structure.

Abstract translation: 本发明的实施例提供了一种垂直磁记录介质，其不仅在中间层的厚度等于或小于约20的介质的区域中彼此之间实现磁记录层中的晶粒的磁隔离 nm，但也具有优异的晶体学结构，表现出中等的中等噪声，优异的热稳定性和高的写入能力。 在一个实施例中，垂直磁记录介质至少具有在基板上依次形成的软磁性底层，第一中间层，第二中间层，第三中间层和磁记录层。 磁记录层由铁磁性晶粒和氧化物或氮化物构成，第三中间层由Ru或Ru合金构成，第二中间层由具有面心立方晶格结构的金属或合金构成， 第一中间层由具有六方密堆积结构的金属或合金构成。

公开(公告)号：US07153546B2

公开(公告)日：2006-12-26

申请号：US10790803

申请日：2004-03-03

Applicant: Kiwamu Tanahashi ,  Atsushi Kikugawa ,  Noboru Shimizu ,  Yukio Honda ,  Yuzuru Hosoe

Inventor： Kiwamu Tanahashi ,  Atsushi Kikugawa ,  Noboru Shimizu ,  Yukio Honda ,  Yuzuru Hosoe

IPC: H05B6/00

CPC classification number: G11B5/667 ,  G11B5/66 ,  G11B5/7325 ,  Y10S428/90

Abstract: Provided are a double-layer perpendicular magnetic recording medium having a high medium S/N at an areal recording density of 50 Gbits or more per square inch, and a magnetic storage apparatus having excellent reliability with a low error rate. The perpendicular magnetic recording medium is formed by sequentially laminating a domain control layer, an amorphous soft magnetic underlayer, an intermediate layer, and a perpendicular recording layer on a substrate. The domain control layer is a triple-layer film formed by laminating a first polycrystalline soft magnetic layer, a disordered antiferromagnetic layer, and a second polycrystalline soft magnetic layer from a substrate side.

公开(公告)号：US06924048B2

公开(公告)日：2005-08-02

申请号：US10413481

申请日：2003-04-15

Applicant: Tetsuya Kanbe ,  Yuzuru Hosoe ,  Ichiro Tamai ,  Yoshio Takahashi ,  Kiwamu Tanahashi ,  Satoshi Matsunuma ,  Yoshihiro Shiroishi

Inventor： Tetsuya Kanbe ,  Yuzuru Hosoe ,  Ichiro Tamai ,  Yoshio Takahashi ,  Kiwamu Tanahashi ,  Satoshi Matsunuma ,  Yoshihiro Shiroishi

IPC: G11B5/66 ,  G11B5/39 ,  G11B5/64 ,  G11B5/65 ,  G11B5/70 ,  G11B5/714 ,  G11B5/738

CPC classification number: G11B5/70 ,  G11B5/714 ,  Y10S428/90

Abstract: A magnetic storage device has a magnetic layer, the magnetic crystal grains of which are separated by a nonmagnetic phase. The typical crystal grain is in the approximate shape of a sphere or an ellipsoid. The thickness of the magnetic crystal grains, which is in the direction perpendicular to the surface or the film, is smaller than that of the thickness of the magnetic film. The ratio of the coercive force, which is measured in the circumferential direction, to the coercive force, which is measured in the radial direction, (the orientation ratio of the coercive force), is larger than 1.0, but preferably nor greater than 3.0. Further, the area fraction of the magnetic grains having an extended axis within 30° from the circumferential direction is equal to or more than 45%.

Abstract translation: 磁存储装置具有磁性层，其磁性晶粒由非磁性相分离。 典型的晶粒呈球体或椭圆体的近似形状。 磁性晶粒的与表面或膜垂直的方向的厚度小于磁性膜的厚度。 在圆周方向上测量的矫顽力与径向测定的矫顽力（矫顽力的取向比）的比例大于1.0，优选为3.0以下。 此外，具有从圆周方向的30°以内的延伸轴的磁性颗粒的面积分数等于或大于45％。

公开(公告)号：US20050142388A1

公开(公告)日：2005-06-30

申请号：US10977552

申请日：2004-10-29

Applicant: Yoshiyuki Hirayama ,  Yuzuru Hosoe ,  Hiroyuki Nakagawa ,  Ikuko Takekuma

Inventor： Yoshiyuki Hirayama ,  Yuzuru Hosoe ,  Hiroyuki Nakagawa ,  Ikuko Takekuma

IPC: G11B5/738 ,  G11B5/64 ,  G11B5/65 ,  G11B5/667 ,  G11B5/673 ,  G11B5/73 ,  G11B5/68

CPC classification number: G11B5/7325 ,  G11B5/65 ,  G11B5/656

Abstract: Embodiments of the invention provide a perpendicular magnetic recording medium that not only attains the magnetic isolation of crystal grains in a magnetic recording layer from one another in a region of the medium in which the thickness of an intermediate layer is equal to or smaller than about 20 nm but also exhibits excellent crystallographic texture and that exhibits small medium noise, excellent thermal stability, and high write-ability. In one embodiment, a perpendicular magnetic recording medium has at least a soft-magnetic underlayer, a first intermediate layer, a second intermediate layer, a third intermediate layer, and a magnetic recording layer successively formed on a substrate. The magnetic recording layer is composed of ferromagnetic crystal grains and oxides or nitrides, the third intermediate layer is composed of Ru or an Ru alloy, the second intermediate layer is composed of a metal or an alloy having the face-centered cubic lattice structure, and the first intermediate layer is composed of a metal or an alloy having the hexagonal close-packed structure.

Abstract translation: 本发明的实施例提供了一种垂直磁记录介质，其不仅在中间层的厚度等于或小于约20的介质的区域中彼此之间实现磁记录层中的晶粒的磁隔离 nm，但也具有优异的晶体学结构，表现出中等的中等噪声，优异的热稳定性和高的写入能力。 在一个实施例中，垂直磁记录介质至少具有在基板上依次形成的软磁性底层，第一中间层，第二中间层，第三中间层和磁记录层。 磁记录层由铁磁性晶粒和氧化物或氮化物构成，第三中间层由Ru或Ru合金构成，第二中间层由具有面心立方晶格结构的金属或合金构成， 第一中间层由具有六方密堆积结构的金属或合金构成。

公开(公告)号：US06773826B2

公开(公告)日：2004-08-10

申请号：US10076420

申请日：2002-02-19

Applicant: Hiroyuki Nakagawa ,  Hiroaki Nemoto ,  Yuzuru Hosoe

Inventor： Hiroyuki Nakagawa ,  Hiroaki Nemoto ,  Yuzuru Hosoe

IPC: G11B564

CPC classification number: G11B5/667 ,  G11B5/7325 ,  Y10T428/12806 ,  Y10T428/12854 ,  Y10T428/12861 ,  Y10T428/12931 ,  Y10T428/265

Abstract: A perpendicular magnetic recording medium and a magnetic storage apparatus, which show an excellent S/N ratio and are suitable for ultra high density magnetic recording, are provided. In the perpendicular magnetic recording medium having a recording layer composed of at least two layers of a main recording layer formed above a substrate and a thermally-stabilizing layer formed on the main recording layer, the thermally-stabilizing layer being formed closer to a surface of the medium than the main recording layer, alloy containing Co and Cr as a main component, which shows a low noise property, is used as the main recording layer, amorphous alloy containing rare earth metals and 3d transition metals as a main component, which is excellent in thermal stability, is used as the thermally-stabilizing layer, and a cap layer formed of alloy containing Co and Cr as a main component is formed on a surface of the thermally-stabilizing layer.

Abstract translation: 提供了显示优异的S / N比并且适用于超高密度磁记录的垂直磁记录介质和磁存储装置。 在具有由形成在基板上形成的主记录层的至少两层和由主记录层形成的热稳定层构成的记录层的垂直磁记录介质中，形成为更靠近表面的热稳定层 使用显示低噪声特性的Co和Cr作为主要成分的合金作为主记录层，使用含有稀土金属和3d过渡金属作为主要成分的非晶态合金作为主记录层，其为 热稳定性优异，作为热稳定层的表面形成由Co和Cr作为主要成分的合金形成的盖层。

公开(公告)号：US06703148B2

公开(公告)日：2004-03-09

申请号：US10212737

申请日：2002-08-07

Applicant: Yoshibumi Matsuda ,  Yotsuo Yahisa ,  Koji Sakamoto ,  Yuzuru Hosoe ,  Akira Kato

Inventor： Yoshibumi Matsuda ,  Yotsuo Yahisa ,  Koji Sakamoto ,  Yuzuru Hosoe ,  Akira Kato

IPC: G11B566

CPC classification number: G11B5/656 ,  G11B5/66 ,  G11B5/732 ,  G11B5/7325 ,  Y10S428/90 ,  Y10T428/12854

Abstract: A magnetic recording medium includes an underlayer of a nonmagnetic alloy containing chromium and titanium, a magnetic layer of a Co—Cr—Pt—Ta or Co—Cr—Pt—B alloy, and an intermediate layer of a Co—Cr—Pt alloy and being disposed between the underlayer and the magnetic layer, thereby carrying out high-density information recording and reproducing operation.

Abstract translation: 磁记录介质包括含有铬和钛的非磁性合金的底层，Co-Cr-Pt-Ta或Co-Cr-Pt-B合金的磁性层和Co-Cr-Pt合金的中间层 并且设置在底层和磁性层之间，从而进行高密度信息记录和再现操作。

公开(公告)号：US06613428B2

公开(公告)日：2003-09-02

申请号：US09849404

申请日：2001-05-07

Applicant: Kazusuke Yamanaka ,  Tomoo Yamamoto ,  Yuzuru Hosoe ,  Nobuyuki Inaba ,  Yasutaro Uesaka ,  Masaaki Futamoto ,  Yoshibumi Matsuda ,  Kenji Furusawa ,  Shinji Narishige

Inventor： Kazusuke Yamanaka ,  Tomoo Yamamoto ,  Yuzuru Hosoe ,  Nobuyuki Inaba ,  Yasutaro Uesaka ,  Masaaki Futamoto ,  Yoshibumi Matsuda ,  Kenji Furusawa ,  Shinji Narishige

IPC: G11B564

CPC classification number: G11B5/64 ,  Y10T428/12465 ,  Y10T428/12986 ,  Y10T428/265 ,  Y10T428/31

Abstract: A thin film magnetic recording medium including a magnetic layer having a fluctuation field defined as S/Xirr, where S is magnetic viscosity and Xirr is irreversible susceptibility Xirr. The fluctuation field of the magnetic layer is not less than 15 oersteds.

Abstract translation: 一种薄膜磁记录介质，包括具有定义为S / Xirr的波动场的磁性层，其中S是磁粘度和Xirr是不可逆的磁化率Xirr。 磁性层的波动场不小于15奥斯特。

公开(公告)号：US06605374B2

公开(公告)日：2003-08-12

申请号：US10137398

申请日：2002-05-03

Applicant: Tetsuya Kanbe ,  Yoshio Takahashi ,  Akira Ishikawa ,  Ichiro Tamai ,  Yuzuru Hosoe ,  Yoshifumi Matsuda ,  Kiwamu Tanahashi ,  Tomoo Yamamoto

Inventor： Tetsuya Kanbe ,  Yoshio Takahashi ,  Akira Ishikawa ,  Ichiro Tamai ,  Yuzuru Hosoe ,  Yoshifumi Matsuda ,  Kiwamu Tanahashi ,  Tomoo Yamamoto

IPC: G11B566

CPC classification number: G11B5/65 ,  G11B5/64 ,  G11B5/653 ,  Y10S428/90 ,  Y10T428/12465 ,  Y10T428/12854 ,  Y10T428/26 ,  Y10T428/265

Abstract: The present invention provides a magnetic recording medium having a magnetic layer deposited on a substrate through a single-layer underlayer or a multilayer-underlayer, the magnetic layer includes magnetic crystal grains having an acicular structure or amorphous magnetic particles, an average grain size of the magnetic grain and a grain-size dispersion normalized by the average grain size are less than 16 nm and less than 0.5, respectively, a value Ku·v/kT which results from dividing a product of a magnetic anisotropy constant Ku and a volume v of the magnetic grain by a product of a Boltzmann constant k and an absolute temperature T is selected to be greater than 60, and a film thickness of the magnetic layer falls within twice of the average grain size. Thus, there can be realized a magnetic recording system in which a media noise can be reduced, a high S/N and a low bit error rate can be obtained and which has a high recording density of 2 gigabits per one square inches and an MTBF (mean time between failure) of higher than 300000 hours.

公开(公告)号：US06569545B1

公开(公告)日：2003-05-27

申请号：US09343721

申请日：1999-06-30

Applicant: Tetsuya Kanbe ,  Yuzuru Hosoe ,  Ichiro Tamai ,  Yoshio Takahashi ,  Kiwamu Tanahashi ,  Satoshi Matsunuma ,  Yoshihiro Shiroishi

Inventor： Tetsuya Kanbe ,  Yuzuru Hosoe ,  Ichiro Tamai ,  Yoshio Takahashi ,  Kiwamu Tanahashi ,  Satoshi Matsunuma ,  Yoshihiro Shiroishi

IPC: G11B566

CPC classification number: G11B5/70 ,  G11B5/714 ,  Y10S428/90

Abstract: A magnetic storage device has a recording density of over 5 gigabits per square inch. In the magnetic layer, the magnetic crystal grains of the granular structure are separated by a nonmagnetic phase. The typical crystal grain is in the approximate shape of a sphere or an ellipsoid. The thickness of the magnetic crystal grains, which is in the direction perpendicular to the surface of the film, is smaller than that of the thickness of the magnetic film. The ratio of the coercive force which is measured in the circumferential direction to the coercive force which is measured in the radial direction, which is the orientation ratio of the coercive force, is larger than 1.0, but preferably not greater than 3.0. Further, the area fraction of the magnetic grains having an extended axis within 30° from the circumferential direction is equal to or more than 45%.

Abstract translation: 磁存储装置具有超过5千兆比特每平方英寸的记录密度。 在磁性层中，粒状结构的磁性晶粒被非磁性相分离。 典型的晶粒呈球体或椭圆体的近似形状。 在与膜表面垂直的方向上的磁性晶粒的厚度小于磁性膜的厚度。 在圆周方向上测量的矫顽力与作为矫顽力的取向比的径向测定的矫顽力的比例大于1.0，优选为3.0以下。 此外，具有从圆周方向的30°以内的延伸轴的磁性颗粒的面积分数等于或大于45％。

公开(公告)号：US06403242B1

公开(公告)日：2002-06-11

申请号：US09524914

申请日：2000-03-14

Applicant: Tetsuya Kanbe ,  Yoshio Takahashi ,  Akira Ishikawa ,  Ichiro Tamai ,  Yuzuru Hosoe ,  Yoshifumi Matsuda ,  Kiwamu Tanahashi ,  Tomoo Yamamoto

Inventor： Tetsuya Kanbe ,  Yoshio Takahashi ,  Akira Ishikawa ,  Ichiro Tamai ,  Yuzuru Hosoe ,  Yoshifumi Matsuda ,  Kiwamu Tanahashi ,  Tomoo Yamamoto

IPC: G11B566

CPC classification number: G11B5/65 ,  G11B5/64 ,  G11B5/653 ,  Y10S428/90 ,  Y10T428/12465 ,  Y10T428/12854 ,  Y10T428/26 ,  Y10T428/265

Abstract: The present invention provides a magnetic recording medium having a magnetic layer deposited on a substrate through a single-layer underlayer or a multilayer-underlayer, the magnetic layer includes magnetic crystal grains having an acicular structure or amorphous magnetic particles, an average grain size of the magnetic grain and a grain-size dispersion normalized by the average grain size are less than 16 nm and less than 0.5, respectively, a value Ku·v/kT which results from dividing a product of a magnetic anisotropy constant Ku and a volume v of the magnetic grain by a product of a Boltzmann constant k and an absolute temperature T is selected to be greater than 60, and a film thickness of the magnetic layer falls within twice of the average grain size. Thus, there can be realized a magnetic recording system in which a media noise can be reduced, a high S/N and a low bit error rate can be obtained and which has a high recording density of 2 gigabits per one square inches and an MTBF (mean time between failure) of higher than 300000 hours.