System and methods for providing a magnetoresistive element having an improved longitudinal bias magnetic field

Abstract

A magnetoresistive element comprising a magnetic sensitive film responding to a magnetic field applied from the outside and a magnetic domain control film applying a bias magnetic field to said magnetic sensitive film in the longitudinal direction in which a sense current flows, wherein in case of assuming that the minimum magnetical thickness of said magnetic domain control film determined in consideration of the minimum magnetic field Hmin required for operation, of a longitudinal bias magnetic field applied to said magnetic sensitive film is &agr; (gauss-&mgr;m), the magnetical thickness x (gauss-&mgr;m) of the magnetic sensitive film given by the product of the remnant magnetization Br (gauss) of said magnetic sensitive film and its film thickness THx (&mgr;m), and the magnetical thickness y (gauss-&mgr;m) of the magnetic domain control film given by the product of the film thickness THy (&mgr;m) of said magnetic domain control film and its remnant magnetization Br (gauss) are set so as to meet “y=−2x+&agr;”. And it is preferable that the relation between the magnetical thickness x (gauss-&mgr;m) of said magnetic sensitive film and the magnetical thickness y (gauss-&mgr;m) of said magnetic domain control film are set so as to meet almost “y=−2x+&agr;” or “−2x+1.1&agr;>=y>=−2x+0.9&agr;”.