Synthesis and characterization of multifermic BiFeO3 powders fabricated by hydrothermal method

Abstract

The influence of processing parameters on phase formation and particle size of hydrothermally synthesized BiFeO3 powders was investigated. BiFeO3 powder was synthesized by dissolving bismuth nitrate and iron nitrate in KOH solution at temperatures ranging from 150 to 225 degrees C. X-ray diffraction patterns and scanning electron microscopy observation indicated that rod-like alpha-Bi2O3 phase was formed at initial stage of reaction and dissolved into ions to form thermodynamically stable BiFeO3 phase. Single-phase perovskite BiFeO3 has been formed using a KOH concentration of 8 M at a temperature of >= 175 degrees C in a 6 h reaction period. BiFeO3 particle growth was promoted by lowering the KOH concentration, or increasing the duration time or reaction temperature. The effects of processing conditions on the formation of crystalline BiFeO3 powders were discussed in terms of a dissolution precipitation mechanism. The magnetization of the BiFeO3 powders at room temperature showed a weak a ferromagnetic nature. (C) 2010 Elsevier Ltd and Techna Group S.r.l. All rights reserved.