Patent ID: 7053429
Filing Date: 2006-05-30
Classification: B82Y,G11B,G11C,H01F,H01L

Abstract:
1. A magnetoresistive device having a resistance that can be changed by applying a magnetic field, said magnetoresistive device comprising: a reference layer, said reference layer having a first magnetization direction that remains substantially fixed when said magnetic field is applied; a switching layer, said switching layer having a second magnetization direction that changes orientation relative to said first magnetization direction when said magnetic field is applied; and a first nonmagnetic conductor layer between said reference layer and said switching layer, wherein at least one of said reference and switching layers includes at least a first ferromagnetic layer, a second ferromagnetic layer, and a second nonmagnetic conductor layer between said first and second ferromagnetic layers, wherein magnetic coupling between said first and second ferromagnetic layers is predominantly magnetostatic, wherein said magnetoresistive device has a first state, in which said magnetoresistive device has a first zero-field resistance, and a second state, in which said magnetoresistive device has a second zero-field resistance, wherein said magnetoresistive device can be switched from said first state to said second state by applying said magnetic field in a first direction, provided that said magnetic field exceeds a first threshold magnitude, and said magnetoresistive device can be switched from said second state to said first state by applying said magnetic field in a second direction opposite to said first direction, provided that said magnetic field exceeds a second threshold magnitude, and wherein said first and second threshold magnitudes are substantially equal.