Patent ID: 7390584
Filing Date: 2008-06-24
Classification: B82Y,G01R,H01L,Y10T

Abstract:
1. A ferromagnetic thin-film based magnetic device including a sequence of layers between opposite ends thereof provided so as to have internal film coupling compensation, said device comprising: a nonmagnetic material intermediate layer, said intermediate layer having two major surfaces on opposite sides thereof substantially parallel to said opposite ends; an initial thin-film of an anisotropic ferromagnetic material against one of said intermediate layer major surfaces; a compensation thin-film of an anisotropic ferromagnetic material against that remaining one of said intermediate layer major surfaces; an antiparallel coupling layer against said compensation thin-film; a subsequent thin-film of an anisotropic ferromagnetic material against said antiparallel coupling layer with said compensation thin-film being less thick than said initial thin-film and less than half as thick as said subsequent thin film, and of thickness sufficient to provide a substantially zero bias value in its magnetoresistance versus externally applied magnetic fields characteristic while free of biasing magnetic fields applied to provide that bias value from a source located so as to be intersected by a plane extendable through any of said initial, compensation or subsequent thin-films parallel to said major surfaces; and an electrode in electrical contact with said device on at least part of one of said ends thereof wherein said thickness of said compensation thin-film is selected such that effective bias magnetic fields thereon and on a selected one of said initial or subsequent thin-films effectively cancel so as to provide said substantially zero bias value.