Patent ID: 8233247

Claim:
A magnetoresistive sensor capable of sensing external magnetic fields when a sense current is applied perpendicular to the planes of the layers in the sensor, the sensor comprising: a substrate; a first sensing structure on the substrate comprising a first ferromagnetic layer comprising an alloy comprising one or more of Co, Fe and Ni and having an in-plane magnetization direction free to rotate in the presence of an applied magnetic field and a first layer consisting essentially of an element selected from the group consisting of Pt, Pd, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Th, Yb, and Lu; a nonmagnetic spacer layer on the first ferromagnetic layer; and a second sensing structure on the substrate comprising a second ferromagnetic layer comprising an alloy comprising one or more of Co, Fe and Ni on the spacer layer and having an in-plane magnetization direction nonparallel to the first ferromagnetic layer's magnetization direction in the absence of an applied magnetic field and free to rotate in the presence of an applied magnetic field and a second layer consisting essentially of an element selected from the group consisting of Pt, Pd, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Th, Yb, and Lu; and wherein the first ferromagnetic layer is in contact with the nonmagnetic spacer layer and the second ferromagnetic layer is in contact with the nonmagnetic spacer layer.