公开(公告)号：US07572527B2

公开(公告)日：2009-08-11

申请号：US11135703

申请日：2005-05-24

申请人： Eric E. Fullerton ,  Byron Hassberg Lengsfield, III ,  David Margulies

发明人： Eric E. Fullerton ,  Byron Hassberg Lengsfield, III ,  David Margulies

IPC分类号： G11B5/66

CPC分类号： G11B5/66 ,  G11B5/656 ,  G11B5/667 ,  G11B5/7325

摘要： A perpendicular magnetic recording disk has an antiferromagnetically-coupled (AFC) recording layer (RL) comprised of lower and upper ferromagnetic layers, each having a hexagonal-close-packed (hcp) crystalline structure and perpendicular magnetic anisotropy, separated by an antiferromagnetically (AF) coupling layer, wherein the lower ferromagnetic layer (LFM) has substantially higher magnetic permeability than the upper ferromagnetic layer (UFM). The AFC RL is located on an actual exchange break layer (EBL) that separates the AFC RL from the disk's soft magnetic underlayer (SUL). The LFM functions as part of an “effective” exchange break layer (EBL) that also includes the actual EBL and the AF-coupling layer, thereby allowing the actual EBL to be made as thin as possible. The hcp LFM promotes the growth of the hcp UFM in the same way the actual EBL does so that its thickness contributes to the thickness necessary to grow the hcp UFM. The effective EBL appears to be magnetically “thin” during the write process and magnetically “thick” during the readback process.

摘要翻译： 垂直磁记录盘具有由下铁磁层和上铁磁层组成的反铁磁耦合（AFC）记录层（RL），每个具有六方密堆积（hcp）晶体结构和垂直磁各向异性，由反铁磁（AF ）耦合层，其中下铁磁层（LFM）具有比上铁磁层（UFM）显着更高的磁导率。 AFC RL位于将AFC RL与磁盘的软磁底层（SUL）分离的实际交换中断层（EBL）上。 LFM作为“有效”交换中断层（EBL）的一部分，该层还包括实际的EBL和AF耦合层，从而使实际的EBL尽可能薄。 hcp LFM以与实际EBL相同的方式促进hcp UFM的增长，使其厚度有助于生长hcp UFM所需的厚度。 在写入过程中，有效的EBL看似磁性很薄，在回读过程中磁性“厚”。

公开(公告)号：US07572526B2

公开(公告)日：2009-08-11

申请号：US11676299

申请日：2007-02-18

申请人： Andreas Klaus Berger ,  Eric E. Fullerton ,  Byron Hassberg Lengsfield, III

发明人： Andreas Klaus Berger ,  Eric E. Fullerton ,  Byron Hassberg Lengsfield, III

IPC分类号： G11B5/66 ,  G11B5/667 ,  G11B5/716 ,  G11B5/673

CPC分类号： G11B5/66

摘要： A perpendicular magnetic recording system uses an exchange-spring type of perpendicular magnetic recording medium. The medium has a recording layer (RL) that includes a lower media layer (ML) and a multilayer exchange-spring layer (ESL) above the ML. The high anisotropy field (high-Hk) lower ML and the multilayer ESL are exchange-coupled across a coupling layer. The multilayer ESL has at least two ESLs separated by a coupling layer, with each of the ESLs having an Hk substantially less than the Hk of the ML. The exchange-spring structure with the multilayer ESL takes advantage of the fact that the write field magnitude and write field gradient vary as a function of distance from the write pole. The thicknesses and Hk values of each of the ESLs can be independently varied to optimize the overall recording performance of the medium.

摘要翻译： 垂直磁记录系统使用交换弹簧式垂直磁记录介质。 介质具有记录层（RL），其包括ML上方的下介质层（ML）和多层交换弹簧层（ESL）。 高各向异性场（high-Hk）较低的ML和多层ESL在耦合层之间交换耦合。 多层ESL具有由耦合层隔开的至少两个ESL，每个ESL具有基本上小于ML的Hk的Hk。 具有多层ESL的交换弹簧结构利用写入场幅度和写场梯度随着与写入极的距离的函数而变化的优点。 可以独立地改变每个ESL的厚度和H k值以优化介质的整体记录性能。

公开(公告)号：US07550210B2

公开(公告)日：2009-06-23

申请号：US11372295

申请日：2006-03-09

申请人： Andreas Klaus Berger ,  Hoa Van Do ,  Eric E. Fullerton ,  Yoshihiro Ikeda ,  Byron Hassberg Lengsfield, III ,  Natacha F. Supper

发明人： Andreas Klaus Berger ,  Hoa Van Do ,  Eric E. Fullerton ,  Yoshihiro Ikeda ,  Byron Hassberg Lengsfield, III ,  Natacha F. Supper

IPC分类号： G11B5/66

CPC分类号： G11B5/66

摘要： A perpendicular magnetic recording medium has an “exchange-spring” type magnetic recording layer (RL) formed of two ferromagnetic layers with substantially similar anisotropy fields that are ferromagnetically exchange-coupled by a nonmagnetic or weakly ferromagnetic coupling layer. Because the write head produces a larger magnetic field and larger field gradient at the upper portion of the RL, while the field strength decreases further inside the RL, the upper ferromagnetic layer can have a high anisotropy field. The high field and field gradient near the top of the RL, where the upper ferromagnetic layer is located, reverses the magnetization of the upper ferromagnetic layer, which then assists in the magnetization reversal of the lower ferromagnetic layer. Because both ferromagnetic layers in this exchange-spring type RL have a high anisotropy field, the thermal stability of the medium is not compromised. The medium shows improved writability, i.e., a low switching field, as well as lower intrinsic media noise, over a medium with a conventional single-layer RL.

摘要翻译： 垂直磁记录介质具有由具有基本相似的各向异性场的两个铁磁层形成的“交换弹簧”型磁记录层（RL），其通过非磁性或弱铁磁耦合层进行铁磁交换耦合。 由于写头在RL的上部产生较大的磁场和较大的场梯度，而在RL内的场强进一步降低，所以上铁磁层可以具有高的各向异性场。 在RL的顶部附近的高场磁场梯度，其中上铁磁层位于其上，反转上铁磁层的磁化，其随后有助于下铁磁层的磁化反转。 由于这种交换弹簧型RL中的两个铁磁层具有高各向异性场，所以介质的热稳定性不受影响。 在具有常规单层RL的介质上，介质显示改进的可写性，即低切换场，以及较低的固有介质噪声。

公开(公告)号：US07532432B2

公开(公告)日：2009-05-12

申请号：US11379858

申请日：2006-04-24

申请人： Yoshihiro Ikeda ,  Byron Hassberg Lengsfield, III ,  James Terrence Olson ,  Petrus Antonius VanDerHeijden

发明人： Yoshihiro Ikeda ,  Byron Hassberg Lengsfield, III ,  James Terrence Olson ,  Petrus Antonius VanDerHeijden

IPC分类号： G11B5/127 ,  G11B5/23

CPC分类号： G11B5/3116 ,  G11B5/11 ,  G11B5/1278 ,  G11B5/3146 ,  G11B5/667

摘要： A perpendicular magnetic recording data storage system combines a perpendicular medium that has a thin low-magnetic-permeability or “soft” underlayer (SUL) with a recording head that has a trailing shield (TS) with a thick throat height, i.e., a thickness in a direction orthogonal to the recording layer of the medium. The SUL is thin enough and has a low enough magnetic permeability to become saturated in a region beneath the trailing gap of the head during writing, but the throat height of the TS is thick enough to prevent the TS from becoming magnetically saturated during writing. The magnetic saturation of the SUL during writing changes the magnetic reluctance such that more of the magnetic flux going through the SUL changes direction (“field undershoot”) and goes to the TS. If the permeability of the SUL is so low (e.g., close to unity) that the SUL does not magnetically saturate, field undershoot may still occur because the reluctance from the SUL to the TS is still smaller than the reluctance from the SUL to the return pole (RP). Field undershoot enables a high write field gradient, which results in narrower magnetic transitions.

摘要翻译： 垂直磁记录数据存储系统将具有薄的低磁导率或“软”底层（SUL）的垂直介质与具有厚的喉部高度的后挡板（TS）的记录头组合，即厚度 在与介质的记录层正交的方向上。 SUL足够薄并且在写入期间具有足够低的磁导率以在头部的拖尾间隙下方的区域饱和，但是TS的喉部高度足够厚以防止TS在写入期间变得磁饱和。 在写入期间SUL的磁饱和度改变磁阻，使得穿过SUL的更多的磁通量改变方向（“场下冲”）并且进入TS。 如果SUL的磁导率如此低（例如，接近于1），SUL不会磁饱和，则由于从SUL到TS的磁阻仍然小于从SUL到返回的磁阻，所以仍然可能发生场下冲 杆（RP）。 场下冲可实现高写磁场梯度，从而导致较小的磁转变。