Sigmalike phase and nanoscale segregation in polycrystalline FexCr1-x films: An element-resolved magnetic and structural study

Complex changes in room-temperature magnetic and chemical order in sputtere d FexCr1-x films (1.0>x >0.24) are revealed by resonant soft x-ray magneto- optical and scattering spectroscopies. A distorted, homogeneous paramagneti c phase at x congruent to 0.55, similar to the bulk sigma phase, is found. Linked chemical and magnetic segregation on either side of this phase are i nterpreted in terms of favorable and frustrated exchange interactions, as i s a net Cr local moment for X greater than or equal to 0.69. Segregated all oys exhibit reversible magnitization originating from weakly coupled, nonco llinear Fe spins.