Structural, microstructural and magneto-electric properties of single-phase BiFeO3 nanoceramics prepared by auto-combustion method

Satya Narayan Tripathy, NIT Rourkela
B. G. Mishra, NIT Rourkela
Mandar M. Shirolkar, University of Science & Technology - China
S. Sen, Central Glass & Ceramic Research Institute - India
Suprem R. Das, Birck Nanotechnology Center, Purdue University
David B. Janes, Birck Nanotechnology Center, Purdue University
Dillip K. Pradhan, NIT Rourkela

Abstract

Polycrystalline nano BiFeO3 powders were synthesized by auto-combustion method using urea as fuel and metal nitrates (Fe(NO3)(3).9H(2)O, Bi(NO3)(3)-5H(2)O) as oxidizers. In order to optimize the single-phase synthesis condition of BiFeO3, different fuel to oxidizer ratios have been investigated. The preliminary structural investigation using X-ray diffraction shows the samples were of single phase and crystallize in rhombohedral structure (R3c). The ferroelectric and antiferromagnetic ordering temperatures of BiFeO3 were found to be 832 degrees C and 364 degrees C respectively, from differential thermal analysis. The temperature dependent dielectric study shows an anomaly around 215 degrees C which corresponds to magneto-electric coupling in the material. Field-emission scanning electron micrographs show effect of fuel to oxidizer ratio on grain size evolution. The ferroelectric hysteresis loops for all the samples were measured at a frequency of 100 Hz confirming the ferroelectric nature. An evidence of magneto-electric coupling was also observed at room temperature from magneto-capacitance measurements. (C) 2013 Elsevier B.V. All rights reserved.

Discipline(s)

Nanoscience and Nanotechnology