Preparation of nanocrystalline BiFeO3 via a simple and novel method and its kinetics of crystallization

Abstract

Abstract The precursor of nanocrystalline BiFeO3 was obtained by solid-state reaction at low heat using Bi(NO3)3·5H2O, FeSO4·7H2O, and Na2CO3·10H2O as raw materials. The nanocrystalline BiFeO3 was obtained by calcining the precursor. The precursor and its calcined products were characterized by differential scanning calorimetry (DSC), Fourier transform-infrared spectroscopy (FT-IR), X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and vibrating sample magnetometer (VSM). The data showed that highly crystallization BiFeO3 with rhombohedral structure (space group R3c (161)) was obtained when the precursor was calcined at 873 K for 2 h. The thermal process of the precursor experienced three steps, which involve the dehydration of adsorption water, hydroxide, and decomposition of carbonates at first, and then crystallization of BiFeO3, and at last decomposition of BiFeO3 and formation of orthorhombic Bi2Fe4O9. The mechanism and kinetics of the crystallization process of BiFeO3 were studied ...