Angular dependence of giant magnetoresistance properties of exchange biased spin valves

Abstract

Giant magnetoresistance (GMR) responses were studied as a function of applied measurement field angle in FeMn and NiMn pinned spin valves. As the measurement field varies away from the pinning field direction, the peak GMR ratio and the free layer coercivity decrease. The GMR curve changes from unsymmetrical to symmetrical with respect to the applied field polarity. The GMR responses from the component parallel to the applied field are proportional to the cosine of the angle between the pinning and the applied field. The results can be described well by a simple vector model, and an empirical method to measure the pinning field rotation is established.