Compositional dependence of hyperfine interactions and magnetoelectric coupling in (BiFeO₃)_x-(BaTiO₃)_1–x solid solutions

In this work the compositional dependence of hyperfine interactions and magnetoelectric coupling in (BiFeO₃)_x-(BaTiO₃)_1-x solid solutions where x = 0.5-0.9 fabricated from commercial BaTiO₃ in terms of the solid-state sintering method at various temperatures and over different time periods is described. In general, as the content of BaTiO₃ increases, a decrease in the hyperfine magnetic field (B_hf) at ⁵⁷Fe nuclei was observed. However, for samples exhibiting lower homogeneity in which the ions of Bi³⁺ and Fe³⁺ are replaced by Ba²⁺ and Ti⁴⁺ with lower probability, higher values of B_hf are obtained. For the sample where x = 0.6 that exhibits the coexistence of rhombohedral, regular and tetragonal phases, the highest value of the α_ME coefficient (3.57 mV/A) was observed, which is more than three times higher when compared to the hitherto published results.