Patent ID: 7450350

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; an antiparallel (AP) pinned structure comprising a first AP-pinned ferromagnetic layer (AP 1 layer) having an in-plane magnetization direction, a second AP-pinned ferromagnetic layer (AP 2 layer) having an in-plane magnetization direction substantially antiparallel to the magnetization direction of the AP 1 layer, and an AP coupling (APC) layer between and in contact with the AP 1 and AP 2 layers, the ferromagnetic AP 2 layer comprising a layer of substantially segregated grains of a ferromagnetic material and grains of one or more elements selected from the group consisting of Cu, Au and Ag, wherein the total amount of said one or more elements is greater than about 10 atomic percent; a free ferromagnetic layer having an in-plane magnetization direction substantially free to rotate in the presence of an external magnetic field; and a spacer layer between the free ferromagnetic layer and the AP 2 layer of the AP-pinned structure.