BiFeO3 perovskites: A multidisciplinary approach to multiferroics

Bismuth ferrite (BiFeO3) is one of the most studied multiferroic system with a large number of published articles. This is mainly because BiFeO3 material possesses both ferromagnetic and ferroelectric properties observed at room temperature, which opens great possibility for industrial and technological applications. Well crystallized single-crystal BiFeO3 nanopowder has been successfully synthesized with the hydrothermal method. The phase composition of the synthesized samples was determined by the x-ray diffraction (XRD) analysis, and the results showed that synthesized material crystallizes in the space group R3c as alpha-BiFeO3 phase, which was confirmed by the previous experiments. In addition, a structure prediction has been performed and 11 additional BiFeO3 modifications have been proposed. In the next phase, an ab initio optimization of predicted structures has been performed and the structure of the gamma-form has been elucidated. Furthermore, electronic and magnetic properties of BiFeO3 were investigated using combination of experimental and theoretical methods. Spectroscopic Ellipsometry has been used to study electronic properties of BiFeO3, while magnetic behavior of synthesized material was investigated by SQUID. Finally, theoretical studies were performed using a full potential linearized augmented plane-waves plus local orbital (FP(L)APW+lo) method, based on density functional theory (DFT).