公开(公告)号：US20040106009A1

公开(公告)日：2004-06-03

申请号：US10601979

申请日：2003-06-24

Applicant: Hitachi, Ltd.

Inventor： Atsushi Nakamura ,  Yoshio Suzuki ,  Kiwamu Tanahashi ,  Yuko Tsuchiya

IPC: G11B005/66

CPC classification number: G11B5/1278 ,  G11B5/012 ,  G11B5/02 ,  G11B5/09 ,  G11B5/11 ,  G11B5/488 ,  G11B5/4886 ,  G11B5/64 ,  G11B5/74 ,  G11B5/82 ,  G11B2005/0002 ,  G11B2005/0005 ,  G11B2005/0029 ,  Y10T428/11

Abstract: A magnetic recording apparatus provides improved resolution and S/N without adversely affecting thermal stability. An angle formed by the direction of easy magnetization of a recording layer and the direction normal to a magnetic recording medium is in the range between 5null and 55null, the easy magnetization direction is from a back surface of the recording layer toward a front surface thereof, and when a recording track direction is from the upstream of the direction of transportation of the medium toward the downstream thereof, an angle formed by the direction of a projection of the easy magnetization direction on the medium plane and the recording track direction is in the range between 0null and 70null.

Abstract translation: 磁记录装置提供改进的分辨率和S / N，而不会不利地影响热稳定性。 由记录层容易磁化的方向和垂直于磁记录介质的方向形成的角度在5°和55°之间的范围内，容易的磁化方向是从记录层的背面向前表面 并且当记录轨道方向从介质的传送方向的上游到其下游时，由介质平面上的容易磁化方向的投影方向和记录轨道方向形成的角度在 范围在0°和70°之间。

公开(公告)号：US20020168547A1

公开(公告)日：2002-11-14

申请号：US10137398

申请日：2002-05-03

Applicant: Hitachi, Ltd.

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

IPC: G11B005/65

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 Kunullv/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.

Abstract translation: 本发明提供一种具有通过单层底层或多层下层沉积在基板上的磁性层的磁记录介质，该磁性层包括具有针状结构或无定形磁性颗粒的磁性晶粒，平均粒径为 磁性晶粒和由平均晶粒尺寸归一化的晶粒尺寸分散度分别小于16nm且小于0.5，由将磁各向异性常数Ku与体积v的积分开而产生的Ku.v / kT值 通过玻耳兹曼常数k和绝对温度T的乘积的磁性粒子选择为大于60，并且磁性层的膜厚度落在平均晶粒尺寸的两倍内。 因此，可以实现可以降低媒体噪声的磁记录系统，可以获得高S / N和低误码率，并且其具有高达2吉比特每平方英寸的高记录密度和MTBF （故障之间的平均时间）高于30万小时。

公开(公告)号：US20020122958A1

公开(公告)日：2002-09-05

申请号：US10025784

申请日：2001-12-26

Applicant: Hitachi, Ltd.

Inventor： Kiwamu Tanahashi ,  Atsushi Kikugawa ,  Yukio Honda

IPC: G11B005/716

CPC classification number: G11B5/66 ,  Y10S428/90

Abstract: Disclosed are a double-layer perpendicular magnetic recording medium having a high medium S/N at a recording density of 50 Gbit or more per square inch and a magnetic storage apparatus with high reliability, which shows a low error rate. In the perpendicular magnetic recording medium in which a pre-coating layer, a soft magnetic underlayer, an intermediate layer, and a perpendicular recording layer are sequentially formed on a substrate, the soft magnetic underlayer contains Fe, Ta and C as main components, a Ta concentration is set to a range from 8 at % to 15 at %, and a ratio of a C concentration to the Ta concentration (C concentration/Ta concentration) is set to a range from 0.5 to 0.9.

Abstract translation: 公开了一种记录密度为每平方英寸50Gbit以上的高介质S / N的双层垂直磁记录介质和具有高可靠性的磁存储装置，其显示出低错误率。 在基板上依次形成预涂层，软磁性底层，中间层和垂直记录层的垂直磁记录介质中，软磁性底层含有Fe，Ta和C作为主要成分， Ta浓度设定在8at％至15at％的范围内，C浓度与Ta浓度的比（C浓度/ Ta浓度）设定为0.5〜0.9。

公开(公告)号：US20040170798A1

公开(公告)日：2004-09-02

申请号：US10790803

申请日：2004-03-03

Applicant: Hitachi, Ltd.

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

IPC: B32B003/02

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：US20040009375A1

公开(公告)日：2004-01-15

申请号：US10357368

申请日：2003-02-04

Applicant: Hitachi, Ltd.

Inventor： Kiwamu Tanahashi ,  Atsushi Kikugawa ,  Yoshio Takahashi ,  Yuzuru Hosoe

IPC: G11B005/72

CPC classification number: G11B5/667 ,  G11B5/66

Abstract: A perpendicular recording medium includes a perpendicular recording layer formed over a substrate through a soft magnetic underlayer, the soft magnetic underlayer then being arranged to include a plurality of soft magnetic layers physically separated by a non-magnetic layer, and further, the soft magnetic layers being formed of nanocrystals, with these arrangements, local magnetic loops are formed between the soft magnetic layers that are adjacent to each other through the non-magnetic layer, thereby suppressing spike noise and modulation that arises from the soft magnetic underlayer.

Abstract translation: 垂直记录介质包括通过软磁性底层在衬底上形成的垂直记录层，然后软磁性底层被布置成包括由非磁性层物理分离的多个软磁性层，此外，软磁性层 由纳米晶体形成，通过这些布置，通过非磁性层在彼此相邻的软磁性层之间形成局部磁环，从而抑制由软磁性底层产生的尖峰噪声和调制。

公开(公告)号：US20040197607A1

公开(公告)日：2004-10-07

申请号：US10833001

申请日：2004-04-28

Applicant: Hitachi, Ltd.

Inventor： Kiwamu Tanahashi ,  Atsushi Kikugawa ,  Yukio Honda ,  Masaaki Futamoto ,  Akira Ishikawa

IPC: G11B005/66

CPC classification number: B82Y25/00 ,  B82Y10/00 ,  G11B5/00 ,  G11B5/3909 ,  G11B5/653 ,  G11B5/667 ,  G11B5/7325 ,  G11B2005/0029

Abstract: A double layer perpendicular magnetic recording medium having a high medium S/N ratio at a recording density of 50 Gb/in2 or higher and a magnetic storage apparatus with a lower error rate and excellent reliability are provided. In a perpendicular magnetic recording medium in which a soft magnetic underlayer 12, an intermediate layer 13, and a perpendicular magnetic recording layer 14 are sequentially formed on a substrate 11, the intermediate layer 13 is made to be a non-magnetic amorphous alloy, in which Ni is a main component and Zr is contained, and the soft magnetic underlayer 12 is constituted of ferromagnetic nan-crystals precipitated by annealing.

Abstract translation: 提供了一种记录密度为50Gb / in 2或更高的具有高介质S / N比的双层垂直磁记录介质和具有较低误码率和优异可靠性的磁存储装置。 在其中在基板11上依次形成软磁性底层12，中间层13和垂直磁记录层14的垂直磁记录介质中，使中间层13成为非磁性非晶合金， 该Ni是主成分，含有Zr，软磁性底层12由通过退火而析出的铁磁性纳米晶体构成。

公开(公告)号：US20030203239A1

公开(公告)日：2003-10-30

申请号：US10413481

申请日：2003-04-15

Applicant: Hitachi, Ltd.

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

IPC: B32B009/00

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

Abstract: In a magnetic storage device, comprising a magnetic recording medium, a drive division that drives said magnetic recording medium in the record direction, a recording division and a regeneration division comprises magnetic head a means that the said magnetic head is put on in the relative motion for the said magnetic recording medium, a signal processing means for carrying out signal input to the said magnetic head and output signal regeneration from the said magnetic head, The said magnetic storage device uses a medium that has a following features; a magnetic layer in the said magnetic recording medium is formed on the substrate through monolayer or multiple underlayer, comprises said magnetic recording medium, the said magnetic layer has granular structure that the magnetic crystal grain is separated by the nonmagnetic phase, and the coercive force orientation ratio is bigger than 1. In the approximation that the said magnetic crystal grain is ellipsoid, the area ratio of the crystal grain of which the extended shaft direction is within 30null from circumferential direction is over 45% or c shaft length radialy measured swells over 1% compared to a shaft length circumferentially measured.

Abstract translation: 在磁存储装置中，包括磁记录介质，在记录方向上驱动所述磁记录介质的驱动分区，记录分区和再生分段，包括磁头a，使所述磁头相对运动 对于所述磁记录介质，信号处理装置用于对所述磁头执行信号输入并输出信号再生。所述磁存储装置使用具有以下特征的介质; 所述磁记录介质中的磁性层通过单层或多层下层形成在基板上，包括所述磁记录介质，所述磁性层具有磁结晶粒由非磁性相分离的颗粒结构，矫顽力取向 比率大于1.在近似所述磁晶粒为椭圆体的情况下，延伸轴方向与圆周方向相距在30°以内的晶粒的面积比超过45％或c轴长度的径向测量膨胀 相对于圆周测量的轴长度为1％。

公开(公告)号：US20020197514A1

公开(公告)日：2002-12-26

申请号：US10076655

申请日：2002-02-19

Applicant: Hitachi, Ltd.

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

IPC: G11B005/667

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.

Abstract translation: 提供了一种双层垂直磁记录介质，其具有每平方英寸50G比特或更高的面积记录密度的高介质S / N，以及具有低误码率的可靠性优异的磁存储装置。 垂直磁记录介质通过在基板上顺序地层叠域控制层，非晶软磁底层，中间层和垂直记录层而形成。 畴控制层是通过从基板侧层压第一多晶软磁层，无序反铁磁层和第二多晶软磁层而形成的三层膜。

公开(公告)号：US20020018920A1

公开(公告)日：2002-02-14

申请号：US09862452

申请日：2001-05-23

Applicant: Hitachi, Ltd.

Inventor： Tomoo Yamamoto ,  Ichiro Tamai ,  Kiwamu Tanahashi ,  Akira Ishikawa

IPC: G11B005/73

CPC classification number: G11B5/7325 ,  G11B5/00 ,  G11B5/656 ,  G11B5/7379 ,  G11B2005/001

Abstract: A magnetic recording apparatus of a large capacity capable of super-high density recording of 10 Gbits or more per one square inch has a magnetic recording medium prepared by forming a Co alloy magnetic layer by way of an underlayer comprising Co or Cr alloy on a substrate, in which an amorphous or micro crystal seed layer containing at least Ti and Al is disposed between the substrate and the underlayer, the magnetic layer has an h.c.p. structure and is grown to (1.1.0) direction parallel with the substrate, the magnetic recording medium of high coercivity and reduced noises and undergoing less effects of thermal fluctuation being provided because of in-plane orientation of the axis of easy magnetization of the magnetic layer and the reduced size of the magnetic crystal grains and dispersion thereof, combination of the magnetic recording medium and the magnetic head having a read only device utilizing the magnetoresistive effect capable of providing a magnetic recording apparatus having a recording density at 10 Gbits or more per one square inch.

Abstract translation: 具有能够每平方英寸高10Gb或更高的超高密度记录的大容量的磁记录装置具有磁记录介质，该磁记录介质是通过在衬底上形成包含Co或Cr合金的底层的Co合金磁性层而制备的 其中至少含有Ti和Al的非晶或微晶晶种子层设置在基底和底层之间，磁性层具有hcp 结构，并且与基板平行生长（1.1.0）方向，由于磁性容易磁化的轴的面内定向，因此提供了高矫顽力和降低的噪声并且发生较少的热波动效应的磁记录介质 磁性晶粒和其分散体的尺寸减小，磁记录介质和具有只读器件的磁头的组合利用磁阻效应，能够提供具有10Gb或更高记录密度的磁记录装置 一平方英寸