Abstract:

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 Néel temperature decreased and the magnetic transition was increasingly diffuse. The Néel temperature was shown to correlate with the volume of the crystallites and the polar displacements of cations.