AP-pinned spin valve GMR and magnetization

Abstract

We present a general analytical coherent rotation model for AP-pinned spin valve magnetoresistance (MR) and magnetization (M). The magnetic structure is determined by minimizing the sum of the Zeeman and the two interfacial exchange energies, σAF and σAP. We compare the model to M(H) and MR(H) taken from an experimental series of AP-pinned spin valves (NiO/AP1/Ru/AP2/Cu/free layer) measured in magnetic fields -5≤H≤5 kOe, and at temperatures 20≤T≤240°C. The Ru thicknesses were 4.5 Å≤tRu≤10.4 Å. We fit the model to data by varying σAF and σAP. The fits reproduce the data quantitatively, and the resulting exchange strengths agree well with published studies of Co/Ru/Co multilayers and ferromagnet/NiO exchange couples. © 2000 American Institute of Physics.