BiFeO3: Synchrotron radiation structure refinement and magnetoelectric geometry

Presently BiFeO3 focuses attention due to its multiferroic nature. This phase shows a highly distorted perovskite crystal structure, with R3c crystal symmetry. Details of the crystallographic structure are required input for a detailed explanation of its remarkable magnetoelectric properties. Present report contributes a high-resolution synchrotron radiation diffraction analysis of the BiFeO3 crystal structure. Single-phased sample was obtained by conventional solid-state reaction under bismuth atmosphere. XRD experiment was performed on beamline 2-1, Stanford Synchrotron Radiation Laboratory, with 12 keV X-rays. For data Rietveld processing, Fullprof software package was applied. Obtained cell parameters (in إ, hexagonal system description) were a = 5.57414(4); c = 13.85882(12). Group-theoretical analysis of BiFeO3 linear magnetoelectric tensor is presented. Only transverse effect is allowed by symmetry. Axial-symmetry polycrystal ceramics cannot show linear magnetoelectric coupling.