Magnetic Properties of Exchange-Biased Multilayer With Perpendicular Magnetic Anisotropy

Perpendicular exchange-biased and multilayers have been fabricated, changing the thickness of the cobalt that is next to the IrMn layer. The crystal structure, interface roughness and magnetic properties were characterized by X-ray diffraction (XRD), X-ray reflectivity (XRR), atomic force microscopy (AFM) and extraordinary Hall Effect (EHE). The multilayers are flat, and the roughness is about 0.2 nm across the 2scanning range. The magnetization reversal is dependent on , and the exchange bias and coercivity vary with . The exchange bias reaches a maximum value (about 13.9 mT) for top-pinned multilayers at , while it reaches a maximum (about 3.5 mT) for bottom-pinned multilayers at . For both stacks the coercivity is maximum (about 30 mT) at , and stable for . These results are well understood in terms of the Co spin orientation at the Co/IrMn interface.