Abstract
A novel approach to synthesize a single-phase orthorhombic perovskite, (La0.9Sr0.1) (Cr-0.85 Fe-0.05 Co0.05Ni0.05)O3-delta, is reported. Samples are synthesized using two groups of precursors, metal nitrates and metal acetates by various routes of sol-gel method. The effects of the anion and synthesis route on the perovskite structure and removal of impurity phase are investigated using X-ray diffractometry and Fourier-transform infrared spectroscopy. Impurity phases, SrCrO4 and CoCr2O4 are observed only for the samples prepared using metal nitrates and ascribed due to the pH dependence of citric acid and the cation-anion bonding character, which also affect the reactivity of the mixed solvents. Variation in cell volume with route is corroborative with route-dependent high frequency stretching modes. A mechanism using a partial-charge model is proposed to explain the results. (c) 2007 Elsevier B.V. All rights reserved.