Patent ID: 8611053

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 antiferromagnetic layer comprising Mn on the substrate; a multilayer reference layer comprising a non-Heusler alloy ferromagnetic layer on and antiferromagnetically exchange coupled to the antiferromagnetic layer and having a fixed in-plane magnetization direction, a Heusler alloy layer having a fixed in-plane magnetization direction parallel to the magnetization direction of the non-Heusler alloy layer, and a substantially non-crystalline X-containing layer between the non-Heusler alloy layer and the Heusler alloy layer wherein X is selected from one or more of Ta, Hf, Nb and B; an electrically conductive spacer layer on and in contact with the Heusler alloy layer; and a free layer on the spacer layer and having an in-plane magnetization direction substantially free to rotate in the presence of an external magnetic field.