Structural, vibrational, electrical and magnetic properties of Bi1−xPrxFeO3

Abstract

Crystalline solid solution of Bi1−xPrxFeO3 (x=0.05, 0.1, and 0.15) ceramics has been successfully synthesized by a low temperature assisted co-precipitation method. Rietveld-refinement of the X-ray diffraction data reveals rhombohedral structure for Bi1−xPrxFeO3 (x=0.05, 0.10) and triclinic for Bi1−xPrxFeO3 (x=0.15). The crystallite sizes of the Bi1−xPrxFeO3 (x=0.05, 0.1 and 0.15) are found to be approximately 33, 27 and 22nm respectively calculated using Debye–Scherrer equation. The SEM images of Bi1−xPrxFeO3 (x=0.05, 0.10 and 0.15) ceramics show grains with almost spherical morphology. 4A1 and 7E Raman modes have been observed in the range 100–650cm−1 and two phonon modes centered around 1150–1450cm−1 have also been observed corresponding to 2A4 (LO), 2E8 (TO) and 2E9 (TO) modes of Bi1−xPrxFeO3 (x=0.05, 0.1 and 0.15). The changes in Raman modes such as prominent frequency shift, line broadening and intensity have been noticed with the increase of Pr concentration in BiFeO3 (BFO) suggesting a structural transformation as revealed by the Rietveld refinement. An anomaly in the temperature dependent dielectric studies has been noticed in all the samples at the vicinity of Neel temperature (TN) indicating a magnetic ordering and an increase in magnetization with increase of Pr concentration is noticed from the room temperature magnetic studies. Further, the leakage current density is found to be reduced with increasing Pr concentration.