公开(公告)号：US4914868A

公开(公告)日：1990-04-10

申请号：US250685

申请日：1988-09-28

申请人： Mark A. Church ,  Annayya P. Deshpande ,  Alain M. Desouches ,  George S. Pal ,  Michael P. Salo ,  Muhammad I. Ullah

发明人： Mark A. Church ,  Annayya P. Deshpande ,  Alain M. Desouches ,  George S. Pal ,  Michael P. Salo ,  Muhammad I. Ullah

IPC分类号： B24B49/10 ,  B23Q17/22 ,  B24B37/04 ,  G11B5/39

CPC分类号： G11B5/3903 ,  B23Q17/22 ,  Y10T29/49036 ,  Y10T29/49048

摘要： A lapping control system for a row of thin film magnetic transducers formed on a substrate. Each of the magnetic transducers comprises a magnetoresistive (MR) element, and the row is supported on a holder which has an elongated H-shaped slot near one edge to form a beam member upon which the row is mounted. The beam member is capable of being deflected in a substantially quadratic curvature when subjected to pressure from a pressure transducer at the middle of the beam member. The resistance of each of the MR elements is measured during lapping, and a control signal is generated to control the pressure transducers to control lapping with proper BALANCE and BOW and to terminate lapping when the desired MR element height is reached.

公开(公告)号：US5552204A

公开(公告)日：1996-09-03

申请号：US372410

申请日：1995-01-13

申请人： Richard H. Ahlert ,  James K. Howard ,  Muhammad I. Ullah ,  Richard D. Umphress

发明人： Richard H. Ahlert ,  James K. Howard ,  Muhammad I. Ullah ,  Richard D. Umphress

IPC分类号： G11B5/72 ,  G11B5/84

CPC分类号： G11B5/72 ,  G11B5/8408 ,  Y10S428/90 ,  Y10T428/2495 ,  Y10T428/24975 ,  Y10T428/265

摘要： A significantly thinner boron carbide overcoat layer is provided for a magnetic disk which has the same durability as thicker prior art overcoat layers for protecting an underlying magnetic layer. By employing adhesion layers selected from the group consisting of Ge, Ru, WTiSi, WTi, Si, and Y between the magnetic layer and the overcoat layer, the durability of the overcoat layer is significantly increased over a single overcoat layer of B4C. Certain process steps in the making of the B4C overcoat layer still further enhance the durability of the B4C overcoat layer by maintaining the disk or substrate specimen at a floating potential in a plasma chamber and employing low levels of argon pressure and sputtering wattage.

公开(公告)号：US5492775A

公开(公告)日：1996-02-20

申请号：US69060

申请日：1993-05-28

申请人： Richard H. Ahlert ,  James K. Howard ,  Todd L. Hylton ,  Michael A. Parker ,  Muhammad I. Ullah

发明人： Richard H. Ahlert ,  James K. Howard ,  Todd L. Hylton ,  Michael A. Parker ,  Muhammad I. Ullah

IPC分类号： C23C14/08 ,  C23C14/58 ,  G11B5/64 ,  G11B5/65 ,  G11B5/66 ,  G11B5/85 ,  G11B5/851

CPC分类号： C23C14/085 ,  C23C14/08 ,  C23C14/58 ,  C23C14/5806 ,  C23C14/584 ,  G11B5/653

摘要： A high-density recording media comprising longitudinally oriented polycrystalline barium ferrite exhibits large coercivity, corrosion resistance, high hardness and durability. Films are prepared by on-axis sputtering at ambient temperatures from stoichiometric targets followed by a post-deposition anneal at approximately 850.degree.C. to induce crystallization. Crystallization yields a magnetic film with large in-plane remanence and a fine scale texturing that greatly improves the tribological performance of barium ferrite disks. Exceptional durability can be achieved on disks without overcoats. Grain sizes as small as 200 .ANG. are produced by doping with small amounts of Cr.sub.2 O.sub.3 or other additives. Coercivities greater than 4000 Oe are achieved even in small grain films.

摘要翻译： 包含纵向取向的多晶钡铁氧体的高密度记录介质具有较高的矫顽力，耐腐蚀性，高硬度和耐久性。 通过在环境温度下从化学计量的靶进行在轴溅射制备膜，然后在约850℃下进行后沉积退火以诱导结晶。 结晶产生具有大的面内剩余磁性膜和精细尺度纹理，大大提高钡铁氧体磁盘的摩擦学性能。 可以在没有大衣的磁盘上实现卓越的耐久性。 通过掺杂少量的Cr 2 O 3或其它添加剂来生产小于200安培的晶粒尺寸。 即使在小颗粒薄膜中也能获得大于4000 Oe的矫顽力。