Multiferroic Bismuth Ferrite Nanoparticles: Rapid Sintering Synthesis, Characterization, and Optical Properties

Abstract

The homogeneous multiferroic BiFeO3 nanoparticles with average particle size of 85 nm have been successfully synthesized by a simple sol-gel route. The prepared sample was characterized by a variety of techniques, such as X-ray diffractometry, thermogravimetric analysis and differential thermal analysis, differential scanning calorimeter analysis, scanning electron microscopy, transmission electron microscopy and X-ray photoelectron spectroscopy. The obtained results shows that rapid sintering and subsequently quenching to room temperature are the two vital important factors for the preparation of pure BiFeO3. The magnetic phase transition (TN = 369 °C) and the ferroelectric phase transition (TC = 824.5 °C) were determined, revealing the antiferromagnetic and ferroelectric nature of the as-prepared BiFeO3 nanoparticles. The optical properties of the nanopowders were investigated. The strong band-gap absorption at 486 nm (2.55 eV) of the BiFeO3 nanoparticles may bring some novel applications.

Easy Synthesis of High-Purity BiFeO3Nanoparticles: New Insights Derived from the Structural, Optical, and Magnetic Characterization

“…However, the maximum magnetic susceptibility at 20 K in the zero field cooling (ZFC) curve, reported by Da Silva et al, differs from that reported at 50 K by Prado et al and that obtained at 85 K by Park et al , At the present, the reported band gap energy values for BiFeO 3 NPs and thin films are contradictory with regard to the expected qualitative dependence on the material dimensions (see Table S1). − ,,− It should be expected that the smaller the NPs the higher the band gap energy value, but the reported values do not show this trend. In the particular case of BiFeO 3 NPs, there is no agreement in theoretical considerations whether the electronic transitions are direct or indirect, see Table S1.…”