Electrical and Magnetic Properties of Multiferroic BiFeO3 Ceramics Prepared Using Sol-Gel Derived Fine Powders
Insulating BiFeO3 ceramics with a small amount of secondary phase Bi2Fe4O9 were prepared by rapid sintering at 840 °C using sol-gel derived fine powders. The ceramics are dense and consist of grains of 3∼8 μm in size. Their leakage current density remains lower than 5.5×10−5 A/cm2 under the applied electrical field below 100 kV/cm. The main conduction mechanism from 50−190 kV/cm is space-charge-limited-current relating to oxygen vacancies. The ceramics exhibit a saturated ferroelectric hysteresis loop with a remanent polarization (2Pr = 22 μC/cm2) under the applied field of 165 kV/cm. Weak ferromagnetism was observed with a remanent magnetization 2Mr of 1.2×10−4 μB/Fe at 300 K and of 1.8×10−4 μB/Fe at 10 K.
F. Chen and Y. J. Qi, "Electrical and Magnetic Properties of Multiferroic BiFeO3 Ceramics Prepared Using Sol-Gel Derived Fine Powders", Applied Mechanics and Materials, Vol. 624, pp. 169-173, 2014