Synthesis of Sr- and Fe-doped LaGaO3 perovskites by the modified citrate method

摘要

Fine particle strontium and iron substituted lanthanum gallates La1-xSrxGa1-yFeyO3-delta, where x = 0.2, 0.4, and 0.6; y = 0.2, 0.4, 0.6, and 0.8, have been synthesized by a modified citrate method. The formation of these powders was confirmed by the X-ray powder diffraction (XRD) and the fine particle of La0.6Sr0.4Ga0.2Fe0.8O3-delta was investigated by scanning electron microscopy (SEM), and particle size analysis. The single phase of La0.8Sr0.2Ga0.4Fe0.6O3-delta, La0.6Sr0.4Ga0.2Fe0.8O3-delta, and La0.4Sr0.6Ga0.2Fe0.8O3-delta powders could be obtained both with and without calcination. The amount of the secondary phase increased when the amount of Sr in La1-xSrxFe0.6Ga0.4O3-delta was more than 0.2 (x > 0.2) and the amount of Fe in La0.6Sr0.4Ga1-yFeyO3-delta and La0.4Sr0.6Ga0.2Fe0.8O3-delta was less than 0.8 (y < 0.8). The results indicated that in the pH range of 1.36-9.27, the single phase of La0.6Sr0.4Ga0.2Fe0.8O3-delta was formed without calcination and the pH had negligible effects on the structure and lattice parameter. The fine particle of these calcined powders (<4 mum) was obtained with the average particle size 1.70 mum at pH = 1.36 and with the average particle size between 0.56-0.60 mum at pH range between 3.39-9.27, and with a lattice parameter about 3.9 Angstrom. (C) 2004 Kluwer Academic Publishers.