公开(公告)号：MY107672A

公开(公告)日：1996-05-30

申请号：MYPI19912080

申请日：1991-11-11

Applicant: IBM

Inventor： DENNIS RICHARD WILHOIT ,  STEVEN EUGENE LAMBERT ,  STUART STEPHEN PAPWORTH PARKIN ,  BRUCE ALVIN GURNEY ,  DANIELE MAURI ,  VIRGIL SIMON SPERIOSU ,  BERNARD DIENY

IPC: G01R33/06 ,  G01R33/09 ,  G11B5/00 ,  G11B5/39

Abstract: A MAGNETORESISTIVE (MR) SENSOR COMPRISING A FIRST AND A SECOND THIN FILM LAYER OF A MAGNETIC MATERIAL (12,16) SEPARATED BY A THIN FILM LAYER OF A NON-MAGNETIC METALLIC MATERIAL (14). THE FIRST FERROMAGNETIC LAYER (12) IS MAGNETICALLY SOFT. THE MAGNETIZATION DIRECTION OF THE FIRST LAYER OF MAGNETIC MATERIAL (12) IS SET SUBSTANTIALLY PERPENDICULAR TO THE MAGNETIZATION OF THE SECOND LAYER OF MAGNETIC MATERIAL (16) AT ZERO APPLIED FIELD, AND THE MAGNETIZATION DIRECTION OF THE SEOCND LAYER OF MAGNETIC MATERIAL (16) IS FIXED. A CURRENT FLOW IS PRODUCED THROUGH THE MR SENSOR, AND THE VARIATIONS IN VOLTAGE ACROSS THE MR SENSOR ARE SENSED DUE TO CHANGES IN RESISTANCE OF THE MR SENSOR PRODUCED BY ROTATION OF THE MAGNETIZATION IN THE FIRST LAYER OF MAGNETIC MATERIAL (12) AS A FUNCTION OF THE MAGNETIC FIELD BEING SENSED. THE VARIATION OF THE RESISTANCE WITH THE ANGLE BETWEEN THE MAGNETIZATION OF THE FIRST AND SECOND LAYERS OF MAGNETIC MATERIAL HAS BEEN DEFINED AS THE SPIN VALVE (SV) EFFECT. IT IS ALSO SHOWN THAT, BY A SUITABLE DIRECTION OF THE CURRENT WITH RESPECT TO THE FIXED MAGNETIZATION, THE (SV) MAGNETORESISTANCE CAN BE ADDED CONSTRUCTIVELY TO THE USUAL ANISOTROPIC MAGNETORESISTANCE. (FIG.5)

公开(公告)号：MY115958A

公开(公告)日：2003-10-31

申请号：MYPI19951407

申请日：1995-05-29

Applicant: IBM

Inventor： BRUCE ALVIN GURNEY ,  DENNIS RICHARD WILHOIT ,  DAVID EUGENE HEIM ,  DANIELE MAURI ,  VIRGIL SIMON SPERIOSU ,  KEVIN ROBERT COFFEY ,  HARALAMBOS LEFAKIS

IPC: G01R33/02 ,  G01R33/09 ,  G11B5/127 ,  G11B5/33 ,  G11B5/39 ,  G11C11/15 ,  H01F10/08 ,  H01F10/32 ,  H01L43/00 ,  H01L43/08 ,  H01L43/10

Abstract: A MAGNETIC RECORDING SYSTEM USES AN IMPROVED SPIN VALVE MAGNETORESISTIVE (SVMR) SENSOR (60). THE SVMR SENSOR HAS A SELF-PINNED LAMINATED LAYER (70) AS THE PINNED FERROMAGNETIC LAYER IN PLACE OF THE CONVENTIONAL SINGLE-LAYER PINNED LAYER. BECAUSE THIS LAMINATED LAYER IS "SELF-PINNED", A HARD BIAS OR EXCHANGE BIAS LAYER IS NOT NEEDED. THE SELF-PINNED LAMINATED LAYER HAS AT LEAST TWO FERROMAGNETIC FILMS (72, 74) ANTIFERROMAGNETICALLY COUPLED TO ONE ANOTHER ACROSS A THIN ANTIFERROMAGNETICALLY (AF) COUPLING FILM (73). SINCE THE TWO FERROMAGNETIC FILMS IN THIS LAMINATED LAYER HAVE THEIR MAGNETIC MOMENTS ALIGNED ANTIPARALLEL, THEIR TWO MAGNETIC MOMENTS CAN BE MADE TO ESSENTIALLY CANCEL BY MAKING THE TWO FERROMAGNETIC FILMS OF SUBSTANTIALLY THE SAME THICKNESS. THE MAGNETIC FIELD ENERGY GENERATED BY THE SIGNAL FIELD ACTING ON THIS LAMINATED LAYER WILL BE SIGNIFICANTLY LESS THAN THE EFFECTIVE ANISOTROPY ENERGY OF THE LAMINATED LAYER. THIS IS BECAUSE THE FORMER IS PROPORTIONAL TO THE DIFFERENCE IN THICKNESSES OF THE TWO FERROMAGNETIC FILMS IN THE LAMINATED LAYER, WHILE THE LATTER IS PROPORTIONAL TO THE SUM OF THE THICKNESSES. AS A RESULT, THE LAMINATED LAYER WILL NOT ROTATE IN THE PRESENCE OF THE SIGNAL FIELD, BUT WILL BE "SELF-PINNED". THE ELIMINATION OF THE EXCHANGE BIAS LAYER PREVIOUSLY RE,QUIRED FOR PINNING ALSO ELIMINATES THE NEED FOR NI-MN AND ITS ASSOCIATED HIGH-TEMPERATURE PROCESS. (FIG. 5)