Saturated and Pinched Ferroelectric Hysteresis Loops in BiFeO3 Ceramics

BiFeO3 (BFO) ceramics were prepared by conventional solid-state reaction method without quenching. The effect of the sintering condition on the phase evolution and the ferroelectric properties of these BFO ceramics were investigated. A pinched polarization - electric field (P-E) hysteresis loop was observed in the sample sintered at high temperature for a short period (820 degrees C for 1 hour) because the domain wall motion is restricted by a large number of ionic defects such as oxygen vacancies. The BFO sample sintered at low temperature for a long period (760 degrees C for 6 hours) displayed a well-saturated P-E hysteresis loop due to its low ionic defect density.