公开(公告)号：JPH10162327A

公开(公告)日：1998-06-19

申请号：JP27770597

申请日：1997-10-09

Applicant: IBM

Inventor： ROBERT EDWARD FONTANA JR ,  STUART STEPHAN PAPPWARTH PERKI

IPC: G01R33/09 ,  G11B5/39 ,  G11C11/16 ,  H01L43/08

Abstract: PROBLEM TO BE SOLVED: To provide a magnetic tunnel joining(MTJ) device which can function as a magnetic reluctance(MR) reading head linearly responding to a magnetic field from a recording medium. SOLUTION: The MTJ device is constituted of an antiferromagnetic layer 116, a fixed ferromagnetic layer 118 which is exchange-biased with the antiferromagnetic layer so that a magnetic moment cannot rotate even in the presence of an applied magnetic field 182, an insulating tunnel barrier layer 120 being in contact with the fixed ferromagnetic layer and a detection ferromagnetic layer 132 having the magnetic moment which is freely rotable in the presence of the applied magnetic field. Respective layers are rectangular shapes having parallel flank edges and the magnetic moment of the detection ferromagnetic layer 132 is bised in a longitudinal direction by a bias ferromagnetic layer 150 magnetostatically connected therewith in the absence of the applied magnetic field. An insulating layer 160 prevents shunt of a detection current and magnetostatically connects the bias ferromagnetic layer with the detection ferromagnetic layer without exerting adverse influence on the resistance of the MTJ MR head.

公开(公告)号：MY110737A

公开(公告)日：1999-02-27

申请号：MYPI19932036

申请日：1993-10-07

Applicant: IBM

Inventor： VIRGIL SIMON SPERIOSU ,  ROBERT EDWARD FONTANA JR ,  BERNARD DIENY ,  WILLIAM CHARLES CAIN

IPC: G01R33/09 ,  G11B5/02 ,  G11B5/39 ,  H01L43/08

Abstract: A MAGNETORESISTIVE READ SENSOR BASED ON THE SPIN VALVE EFFECT IN WHICH A COMPONENT OF THE READ ELEMENT RESISTANCE VARIES AS THE COSINE OF THE ANGLE BETWEEN THE MAGNETIZATION DIRECTIONS IN TWO ADJACENT MAGNETIC LAYERS IS DESCRIBED. THE SENSOR READ ELEMENT INCLUDES TWO ADJACENT FERROMAGNETIC LAYERS SEPARATED BY A NON-MAGNETIC METALLIC LAYER, THE MAGNETIC EASY AXIS OF EACH OF THE FERROMAGNETIC LAYERS BEING ALIGNED ALONG THE LONGITUDINAL AXIS OF THE FERROMAGNETIC LAYERS AND PERPENDICULAR TO THE TRACKWIDTH OF AN ADJACENT MAGNETIC STORAGE MEDIUM. THE SENSE CURRENT FLOWING IN THE SENSOR ELEMENT GENERATES A BIAS FIELD WHICH SETS THE DIRECTION OF MAGNETIZATION IN EACH FERROMAGNETIC LAYER AT AN EQUAL, BUT OPPOSITE, ANGLE WITH RESPECT TO THE MAGNETIC EASY AXIS THUS PROVIDING AN ANGULAR SEPARATION OF 2 IN THE ABSENCE OF AN APPLIED MAGNETIC SIGNAL.THE MAGNETIZATIONS OF BOTH FERROMAGNETIC LAYERS ARE RESPONSIVE TO AN APPLIED MAGNETIC FIELD TO CHANGE THEIR ANGULAR SEPARATION BY AN AMOUNT 2.(FIG 3)

公开(公告)号：SG79174A1

公开(公告)日：2001-03-20

申请号：SG1996000130

申请日：1994-03-22

Applicant: IBM

Inventor： ROBERT EDWARD FONTANA JR ,  CHERNGYE HWANG ,  VLAD JOSEPH NOVOTNY ,  TIMOTHY CLARK REILEY ,  CELIA ELIZABETH YEACK-SCRANTON ,  CLINTON DAVID SNYDER

IPC: G11B5/10 ,  G11B5/187 ,  G11B5/255 ,  G11B5/31 ,  G11B5/39 ,  G11B5/48

Abstract: A contact recording disk file uses an integrated head-suspension assembly having a head carrier with a dual-layer wear pad for contacting the disk during read and write operations. The outer wear layer of the pad is relatively soft and wear prone compared to a harder and more wear-resistant inner layer. The outer wear layer wears away at a relatively rapid rate during initial wear-in of the head carrier. In this manner the head pole pieces, which extend into the wear pad, are rapidly put into contact with the disk, thereby compensating for initial misalignment of the wear pad with the surface of the disk. The inner wear layer then provides wear resistance over the life of the disk file. In the preferred embodiment, both the outer and inner wear layers are formed of essentially amorphous carbon doped with different amounts of hydrogen.

公开(公告)号：SG90188A1

公开(公告)日：2002-07-23

申请号：SG200006269

申请日：2000-10-31

Applicant: IBM

Inventor： ERIC GORDON BAUGH ,  MYRON DALE FLICKNER ,  ROBERT EDWARD FONTANA JR ,  STEPHEN ARNOLD OLSON ,  GURINDER PAL SINGH

IPC: G11B21/24 ,  G11B5/455 ,  G11B5/48 ,  G11B33/10

Abstract: A method and tool for measurement of the roll static attitude and y-misalignment of magnetic recording sliders within the head stack assembly having reference elements placed on the deposited end of the magnetic recording slider, which are optically analyzed by a video camera connected to a computer. For fast measurement the head stack assembly is clamped in a fixture mounted on motorized stages, which move each slider into the measurement position. In a two step imaging and analyzing process, the orientation and location of one or more edges of the reference element are computed and compared with known control parameters.

公开(公告)号：SG87011A1

公开(公告)日：2002-03-19

申请号：SG1998004218

申请日：1998-10-16

Applicant: IBM

Inventor： ROBERT EDWARD FONTANA JR ,  STUART STEPHEN PAPWORTH PARKIN ,  CHING HWA TSANG ,  MASON LAMAR WILLIAMS

IPC: G11B5/39 ,  G11B5/33

Abstract: A magnetic tunnel junction (MTJ) magnetoresistive read head (25) for a magnetic recording system has the MTJ sensing or free ferromagnetic layer (132) also functioning as a flux guide to direct magnetic flux from the magnetic recording medium (16) to the tunnel junction. The MTJ fixed ferromagnetic layer (118) and the MTJ tunnel barrier layer (120) have their front edges substantially coplanar with the sensing surface (200) of the head (25). Both the fixed and free ferromagnetic layers (118, 132) are in contact with opposite surfaces of the MTJ tunnel barrier layer (120) but the free ferromagnetic layer extends beyond the back edge (212, 208) of either the tunnel barrier layer or the fixed ferromagnetic layer, whichever back edge is closer to the sensing surface (200). This assures that the magnetic flux is non-zero in the tunnel junction region. The magnetization direction (119) of the fixed ferromagnetic layer (118) is fixed in a direction generally perpendicular to the sensing surface and thus to the magnetic recording medium (16), preferably by interfacial exchange coupling with an antiferromagnetic layer (116). The magnetization direction (133) of the free ferromagnetic layer (132) is aligned in a direction generally parallel to the surface of the medium (16) in the absence of an applied magnetic field and is free to rotate in the presence of applied magnetic fields from the medium. A layer of high coercivity hard magnetic material adjacent the sides of the free Ferromagnetic layer (132) longitudinally biases the magnetization of the free ferromagnetic layer in the preferred direction.