Size-dependent properties of multiferroic BiFeO3 nanoparticles

BiFeO3 nanoparticles prepared by a modified Pechini method display strong size-dependent properties. The rhombohedral distortion from cubic structure is reduced by decreasing particle size accompanied by decreasing polarization inferred from atomic displacements found by Rietveld refinement of X-ray powder diffraction data. With decreasing crystallite size, the Neel temperature decreased and the magnetic transition was increasingly diffuse. The Neel temperature was shown to correlate with the volume of the crystallites and the polar displacements of cations.