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)