Multiferroic properties of Bi1 − xDyxFeO3 (x = 0–0.2) ceramics at various temperatures

Insulated Bi1 − xDyxFeO3 (x = 0–0.2) were prepared to study their multiferroic properties at various temperatures. Bi1 − xDyxFeO3 (x = 0–0.08) shows rhombohedral phase, ferroelectric polarization of > 18 μC/cm2, and piezoelectric d33 value of > 35 pC/N at room temperature. After the polarized ceramics were annealed at various high temperatures, the piezoelectric d33 changes suggest that ferroelectric component exists below 700 °C. There are ferroelectric phase and PZT-like anti-polar orthorhombic phase together in Bi1 − xDyxFeO3 (x = 0.11–0.17), although only ferroelectric phase contributes polarization and d33 which decreases with Dy concentration at this two-phase coexistence region. Finally, Bi1 − xDyxFeO3 (x = 0.2) transforms to non-polar orthorhombic phase according to structural and electric measurements.

► Bi1 − xDyxFeO3 (x = 0–0.08) shows large polarization and d33 values. ► Ferroelectric component exists at 20–700 °C when x = 0–0.08. ► Ferroelectric phase and anti-polar orthorhombic phase coexist at x = 0.11–0.17.