A simple and efficient preparation of LaFeO3 nanopowders by glycine-nitrate process: Effect of glycine concentration

LaFeO3 perovskites have been prepared by the glycine-nitrate process (GNP) at various glycine-to-nitrate molar ratios. The perovskites have been systematically characterized by X-ray diffraction, BET surface area, scanning electron microscopy, transmission electron microscopy and temperature-programmed reduction to study the effect of glycine concentration on various properties of LaFeO3. The X-ray diffraction patterns of the as-prepared and calcined samples show the formation of orthorhombic phase without any impurities. The BET specific surface areas of various perovskites increased with an increase in glycine-to-nitrate ratio (GNR) of 2.0 but were nearly constant at higher ratios. The scanning electron microscopy indicates that the prepared material is flake-like at GNRs <= 1.5 and exists as agglomerated particles at GNRs >= 2.0. The particle size of the as-prepared samples was in the range of 30-130 nm depending on the GNR and the calcined samples exhibited particle size in the range of 60-160 nm. The samples that were prepared at GNR <= 1.5 did not show any peaks in temperature-programmed reduction, but the samples prepared at a GNR of 2.0 and above showed the reduction of Fen+. (C) 2011 Elsevier Ltd and Techna Group S.r.l. All rights reserved.