Chemical ordering and magnetic phase transitions in multiferroic BiFeO3-AFe1/2Sb1/2O3 (A-Pb, Sr) solid solutions fabricated by a high-pressure synthesis

Abstract

Ceramic samples of BiFeO3-based perovskite solid solutions with the highly ordered complex perovskites PbFe[Formula: see text]Sb[Formula: see text]O3 (PFS) and SrFe[Formula: see text]Sb[Formula: see text]O3 (SFS) were obtained using high-pressure synthesis at 4-6 GPa. Mössbauer studies revealed that BiFeO3-SFS compositions are characterized by a larger compositional inhomogeneity as compared to BiFeO3-PFS ones. In line with this result, concentration dependence of the magnetic phase transition temperature TN for BiFeO3-SFS compositions is close to the [Formula: see text] dependence for BiFeO3 solid solution with disordered perovskite PbFe[Formula: see text]Nb[Formula: see text]O3 (PFN). In contrast to this [Formula: see text] dependence for BiFeO3-PFS compositions nicely follows the theoretical [Formula: see text] dependence calculated for the case of the ordered distribution of Fe[Formula: see text] and non-magnetic Sb[Formula: see text] ions in the lattice (chemical ordering).