Effect of Eu substitution on the crystal structure and multiferroic properties of BiFeO3

Single-phase Bi _1−xEu _xFeO ₃ (0 ≤ x ≤ 0.3) multiferroic ceramics were prepared to study the effects of Eu substitution on their crystal structure and ferroelectromagnetic behavior. X-ray diffraction studies revealed a sequence of the composition-driven structural phase transitions R3c → Pn2 ₁ a (occurs at x = 0.2). Magnetic measurements revealed that Eu substitution can effectively induce the appearance of the spontaneous magnetization, which was significantly enhanced upon the composition-driven transition from a rhombohedral to an orthorhombic phase. The leakage current was found to be reduced on increased Eu concentration. The electric hysteresis loops were obtained in the Bi _1−xEu _xFeO ₃ ceramics, but the loops were not really saturated. The magnetoelectric coupling in Eu-doped BiFeO ₃ was estimated by the changes in the dielectric constant with an external magnetic filed.