Field effects on spontaneous magnetization reversal of bulk BiFe0.5Mn0.5O3, an effective strategy for the study of magnetic disordered systems

We report a comprehensive study of the spontaneous magnetization reversal (MRV) performed on the disordered polycrystalline perovskite BiFe0.5Mn0.5O3, an intriguing compound synthesized in high pressure-high temperature conditions. In disordered systems, the origin of MRV is not completely clarified, yet. In BiFe0.5Mn0.5O3, compositional disorder involves the ions on the B-site of the perovskite determining the presence of mesoscopic clusters, characterized by high concentrations of iron or manganese and thus by different resultant magnetization. This leads to the observation of two singular fields H1 and H2 dependent on the degree of inhomogeneity, unpredictably changing from sample to sample due to synthesis effects. These fields separate different magnetic responses of the system; for applied fields H