Сorrelation between structural phase coexistence and magnetic response of Eu-doped BiFeO3 at the morphotropic phase boundary

Bi1-xEuxFeO3 ceramic samples with x = 0.1–0.2 have been synthesized to investigate the correlation between the multiphase coexistence and magnetic response. X-ray diffraction and Raman scattering spectra reveal the structural transition from the R3c rhombohedral to Pnma nonpolar orthorhombic structures via partial formation of Pbam antipolar orthorhombic structure with increasing of Eu concentration, thus disclosing the mixed phase state in the composition range of 0.10 ≤ x ≤ 0.18. The magnetic measurement at a high magnetic field reveals a weak ferromagnetic behavior; the magnetization reaches maximum value in phase mixture compounds and then decreases in a single phase compound. The different magnetic response under high and low applied fields is explained in terms of the phase boundary (PB) spins and the intrinsic antiferromagnetic spins. The characteristic of the PB spins contributing to the magnetic properties have been determined by the study on the magnetic aging effect, electric field-induced phase transition, and field step-dependent hysteresis loops.