公开(公告)号：MY113475A

公开(公告)日：2002-03-30

申请号：MYPI19951135

申请日：1995-04-28

Applicant: IBM

Inventor： ROBERT EDWARD FONTANA ,  TSANN LIN ,  CHING HWA TSANG

IPC: G01R33/09 ,  G11B5/39 ,  G11C11/15 ,  H01L43/10

Abstract: AN IMPROVED SPIN VALVE (SV) MAGNETORESISTIVE ELEMENT HAS ITS FREE FERROMAGNETIC LAYER (63) IN THE FORM OF A CENTRAL ACTIVE REGION WITH DEFINED EDGES AND END REGIONS THAT ARE CONTIGUOUS WITH AND ABUT THE EDGES OF THE CENTRAL ACTIVE REGION. A LAYER (91) OF ANTIFERROMAGNETIC MATERIAL, PREFERABLY A NICKEL-MANGANESE (NI-MN) ALLOY, IS FORMED ON AND IN CONTACT WITH THE FERROMAGNETIC MATERIAL IN THE END REGIONS FOR EXCHANGE COUPLING WITH THE END REGIONS TO PROVIDE THEM WITH A LONGITUDINAL BIAS OF THEIR MAGNETIZATIONS. THE PINNED FERROMAGNETIC LAYER (70) IN THE SV ELEMENT IS PINNED BY EXCHANGE COUPLING WITH A DIFFERENT LAYER OF ANTI FERROMAGNETIC MATERIAL, PREFERABLY AN IRON-MANGANESE (FE-MN) ALLOY. THIS MATERIAL HAS A SUBSTANTIALLY DIFFERENT NEEL TEMPERATURE FROM THAT OF THE ANTI FERROMAGNETIC MATERIAL ON THE END REGIONS. THE PROCESS FOR MAKING THE SV ELEMENT INCLUDES HEATING TO DIFFERENT PREDETERMINED TEMPERATURES IN THE PRESENCE OF AN APPLIED MAGNETIC FIELD TO ORIENT THE MAGNETIZATIONS OF THE FREE AND PINNED LAYERS IN THE PROPER DIRECTION. THE SV ELEMENT MAY BE USED AS A SENSOR FOR READING DATA IN MAGNETIC RECORDING SYSTEMS.(FIG. 5)

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.

公开(公告)号：IN168073B

公开(公告)日：1991-02-02

申请号：IN641MA1986

申请日：1986-08-07

Applicant: IBM

Inventor： CHING HWA TSANG

IPC: G01R33/09 ,  G11B5/39 ,  H01L43/08 ,  H04R23/00

Abstract: A magnetoresistive (MR) read transducer assembly comprises a thin film MR layer (10) which is longitudinally biased only in the end regions (12) by exchange bias developed by a thin film of antiferro­magnetic material (16) that is deposited in direct contact with the MR layer in the end regions. The longitudinal bias is of a level suffi­cient to maintain the end regions of the MR layer in a single domain state and thereby induce a single domain state in the central region (14) of the MR layer. Transverse bias is produced within the central region of the MR layer of a level sufficient to maintain that region of the MR layer in a linear response mode. Spaced conductive elements (18,20) are connected to the MR layer within the central region to define a detection region so that sensing means connected to the con­ductive elements can determine the resistance changes in the detection region of the MR layer resulting from the magnetic fields intercepted by the MR layer.