Influence of temperature on the texture and magnetic properties of IrMn-based spin-valve multilayers

Abstract

Top-pinning, spin-valve multilayer films with the structure Ta (5 nm)/Co75Fe25 (5 nm)/Cu (2.5 nm)/Co75Fe25 (5 nm)/Ir20Mn80 (12 nm)/Ta (8 nm) were prepared by high-vacuum DC magnetron sputtering. The effects of temperature on the film microstructure and magnetic properties were investigated by X-ray diffraction, atomic force microscopy, transmission electron microscopy, and vibrating sample magnetometry. The effects of temperature on the thermomagnetic stability of the spin-valve multilayers were studied based on the residence time of the sample in a reverse saturation field. The following effects were observed with increasing temperature: the IrMn(111) texture weakened; surface/interface roughness increased; interfacial diffusion was enhanced; the coercivities of the exchange bias field and pinned layer decreased; the coercivity of the free layer increased; relaxation became more obvious; and thermomagnetic stability decreased.