Magnetic phase diagram mapping in Fe_1-xRh_x composition-spread thin films

We have fabricated high-quality polycrystalline Fe1-xRhx composition-spread thin films by cosputtering Fe and Rh, and investigated their structural and magnetic transformations as a systematic function of composition. With increasing Rh concentration, Fe1-xRhx thin film undergoes from an alpha? phase to a disordered gamma phase and also shows a magnetic transition from a ferromagnetic phase to a paramagnetic phase. Vibrating-sample magnetometry and x-ray magnetic circular dichroism measurements show an antiferromagnetic-ferromagnetic transition in the range of 0.52 < x < 0.58 in the Fe1-xRhx composition gradient at room temperature. Based on our structural and magnetic property mapping, we construct a thin-film phase diagram of Fe1-xRhx. Compared to reported results in bulk alloys, the antiferromagnetic-ferromagnetic transition in the Fe1-xRhx thin films was found to occur at slightly higher Rh concentrations, while the boundary between the pure gamma phase and the alpha?/gamma mixed phase region is shifted to the lower concentration Rh.