Magnetic And Dielectric Properties Of Multiferroic BiFeO3 nanoparticles Synthesized By A Novel Citrate Combustion Method

Department of Physics, Indian Institute of Technology, Kanpur 208016, India

Adv. Mater. Lett., 2012, 'ICNANO 2011', 3 (6), pp 533-538

DOI: 10.5185/amlett.2012.icnano.242

Publication Date (Web): Sep 23, 2012

Copyright © IAAM-VBRI Press

E-mail: slayek@iitk.ac.in

Abstract

Single phase BiFeO₃ nanoparticles have been successfully synthesized for the first time by a novel citrate combustion method without using any solvent. Well mixed metal nitrates along with citric acid which is used as fuel combust to give BiFeO₃ nanoparticles after annealing. These particles are single phase in nature and crystallize in the rhombohedral distorted perovskite structure (space group-R3c) which has been confirmed by the Rietveld refinement of the room temperature powder x-ray diffraction data. Nearly spherical particles of average particle size 47 nm have been seen from transmission electron micrograph. Room temperature magnetic hysteresis measurement shows weak ferromagnetism though the magnetization does not saturate upto 1.75 T applied field. The coercive field value is calculated to be 180 Oe which is 3 times higher than that prepared by solvent free combustion method using glycine. ⁵⁷Fe Mössbauer spectrum can be fitted with a sextet corresponding to single magnetic state of hyperfine field about 49.5 T corresponding to Fe³⁺ state of the iron atom. The dielectric relaxation and ac conductivity as a function of frequency have been discussed. High dielectric permittivity has not been found in these nanoparticles like other reported BiFeO₃  ceramics.

Keywords

BiFeO3, combustion method, multiferroic, VSM, spin spiral structure, Mossbauer spectroscopy.