AP-pinned spin valve GMR and magnetization

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, sigma(AF) and sigma(AP). 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 less than or equal to H less than or equal to 5 kOe, and at temperatures 20 less than or equal to T less than or equal to 240 degrees C. The Ru thicknesses were 4.5 Angstrom less than or equal to t(Ru) less than or equal to 10.4 Angstrom. We fit the model to data by varying sigma(AF) and sigma(AP). 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. (C) 2000 American Institute of Physics. [S0021-8979(00)73508-0].