Synthesis of Sr- and Fe-doped LaGaO<inf>3</inf>perovskites by the modified citrate method

Abstract

Fine particle strontium and iron substituted lanthanum gallates La1-xSrxGa1-yFeyO3-δwhere 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-δwas investigated by scanning electron microscopy (SEM), and particle size analysis. The single phase of La0.8Sr0.2Ga0.4Fe0.6O3-δ, La0.6Sr0.4Ga0.2Fe0.8O3-δ, and La0.4Sr0.6Ga0.8Fe0.8O3-δpowders 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-δwas more than 0.2 (x > 0.2) and the amount of Fe in La0.6Sr0.4Ga1-yFeyO3-δand La0.4Sr0.6Ga0.2Fe0.8O3-δwas 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-δwas formed without calcination and the pH had negligible effects on the structure and lattice parameter. The fine particle of these calcined powders (<4 μm) was obtained with the average particle size 1.70 μm at pH = 1.36 and with the average particle size between 0.56-0.60 μm at pH range between 3.39-9.27, and with a lattice parameter about 3.9 Å. © 2004 Kluwer Academic Publishers.