Multiferroicity in polarized single-phase Bi₀.₈₇₅Sm₀.₁₂₅FeO₃ceramics

Abstract

Single-phase Bi₀.₈₇₅Sm₀.₁₂₅FeO₃ceramics were prepared, and their crystal structure and multiferroic properties were studied. The triclinic structure with P1 space group was confirmed in the ceramics by refining the x-ray diffraction data. Large piezoelectric d₃₃coefficient of 29 pC/N, together with high remnant polarization of 15.09 μC/cm², was measured at room temperature, suggesting the existence of long-range ferroelectric order on a macroscopic scale. The observed small remnant magnetization of 0.071 emu/g at room temperature as a result of the collapse of the space-modulated spin structure indicated the presence of long-range canted antiferromagnetic order on a macroscopic scale. The coexistence of the long-range ferroelectric and canted antiferromagnetic orders allowed the magnetoelectric effect below the antiferromagnetic Néel temperature of 265 °C near which magnetoelectric coupling was obvious.