Low temperature synthesis of pure SrSnO3 and the (BaxSr1-x)SnO3 solid solution by the polymerized complex method

Pure SrSnO3, and (Ba1-xSrx)SnO3 with compositions (x =0, 0.25, 0.5, 0.75 an d 1) were directly prepared by the polymerized complex (PC) technique based on a modified Pechini-type reaction route at the relatively low temperatur e of 600 degrees C. Anhydrous citric acid (CA) was added to SnCl(4)xH(2)O d issolved in ethylene glycol (EG). After complete dissolution, BaCO3 and SrC O3 powders were added according to the desired mole ratio of the solid solu tion, and the mixture was stirred at 80 degrees C for several hours until t he solution became transparent. This solution, with a molar ratio (Ba + Sr) /Sn/CA/EG = 1/1/10/40, was heated at 130 degrees C to produce a yellowish t ransparent resin without any precipitation. The pyrolysis of the resin at 3 50 degrees C yielded a powder precursor for (Ba,Sr)SnO3 Pure SrSnO3 is foun d with a pseudo cubic structure, which has some deviation from the perfect cubic lattice. X-ray diffraction (XRD) indicated the formation of pseudo-cu bic (Ba,Sr)SnO3, when the barium, strontium-tin precursor was heat treated in air at 600 degrees C or above for 2 h. The solid solution of (Ba,Sr)SnO3 exhibited a transition from the ideal cubic structure to a pseudo cubic st ructure. (C) 2000 Elsevier Science B.V. All rights reserved.