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2 Materials Science Poland

2 2013

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Investigation on multiferroic properties of BiFeO3 ceramics

Shariq M., Kaur D., Chandel V. S., Siddiqui M. A.

Materials Science Poland

2013

Vol. 31, No. 3

471--475

BiFeO3 polycrystalline ceramics was prepared by solid-state reaction method and its structural, optical and magnetic properties were investigated. BiFeO3 was synthesized in a wide range of temperature (825 – 880 °C) and a well crystalline phase was obtained at a sintering temperature of 870 °C. X-ray diffraction patterns of the samples were recorded and analyzed for the confirmation of crystal structure and the determination of the lattice parameters. The average grain size of the samples was found to be between 1 – 2 μm. The determined value of direct bandgap of BiFeO3 ceramics was found to be 2.72 eV. The linear behavior of M-H curve at room temperature confirmed antiferromagetic properties of the BiFeO3 (BFO). S shaped M-H curve was obtained at a temperature of 5 K. In the whole temperature measurement range (5 – 300 K) of M-T, no anomalies were observed due to high Curie temperature and Neel temperature of the BiFeO3.

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

Chaudhari Y. A., Mahajan C. M., Abuassaj E. M., Jagtap P. P., Patil P. B., Bendre S. T.

Materials Science Poland

2013

Vol. 31, No. 2

221--225

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 “e” and dielectric loss “tan d” 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.