Ferroelectric and dielectric properties of nanocrystalline BiFeO3 multiferroic ceramics synthesized by solution combustion method (SCM)

Nanocrystalline multiferroic BiFeO₃ ceramics was prepared by a novel solution combustion method (SCM). The X-ray diffraction (XRD) studies on structural properties of the synthesized ceramics reveal that the BiFeO₃ ceramics has rhombhohedral perovskite structure with an average crystallite size of 15 nm. The ferroelectric P-E hysteresis loop measurement at room temperature shows unsaturated behavior with a partial reversal of polarization. Investigations on temperature dependence of dielectric constant in BiFeO₃ demonstrate a clear dielectric anomaly at approximately around 380 °C, which corresponds to antiferromagnetic to paramagnetic phase transition (TN) and also evidences a possible coupling among the electric and magnetic dipoles of BiFeO₃. A room temperature variation of dielectric constant “?” and dielectric loss “tan δ” as a function of frequency in the range of 100 Hz — 1 MHz, confirms that both dielectric constant and loss are strong functions of frequency.