SYNTHESIS OF NANOSIZED BISMUTH FERRITE (BiFeO3) BY A COMBUSTION METHOD STARTING FROM Fe(NO3)(3)center dot 9H(2)O-Bi(NO3)(3)center dot 9H(2)O-GLYCINE OR UREA SYSTEMS

摘要

Two bismuth ferrite potential precursors systems, namely Fe(NO3)(3)center dot 9H(2)O-Bi(NO3)(3)center dot 9H(2)O-glycine/urea with different metal nitrate/organic compound molar ratios have been investigated in order to evaluate their suitability as BiFeO3 precursors. The presence into the precursor of both reducing (glycine and urea) and oxidizing (NO3-) components, modifies dramatically their thermal behaviour comparative with the raw materials, both from the decomposition stoichiometries and temperature occurrence intervals points of view. Also, the thermal behaviour is dependent on the fuel nature but practically independent with the fuel content. The fuel nature influences also some characteristics of the resulted oxides (phase composition, morphologies). In the case of the oxides prepared using urea as fuel, a faster evolution toward a single phase composition with the temperature rise is evidenced, the formation of the BiFeO3 perovskite phase being completed in the temperature range of 500-550 degrees C.