Low temperature synthesis of pure SrSnO 3 and the (Ba xSr 1− x)SnO 3 solid solution by the polymerized complex method

Abstract

Pure SrSnO 3 and (Ba 1− x Sr x )SnO 3 with compositions ( x=0, 0.25, 0.5, 0.75 and 1) were directly prepared by the polymerized complex (PC) technique based on a modified Pechini-type reaction route at the relatively low temperature of 600°C. Anhydrous citric acid (CA) was added to SnCl 4. xH 2O dissolved in ethylene glycol (EG). After complete dissolution, BaCO 3 and SrCO 3 powders were added according to the desired mole ratio of the solid solution, and the mixture was stirred at 80°C for several hours until the solution became transparent. This solution, with a molar ratio (Ba+Sr)/Sn/CA/EG=1/1/10/40, was heated at 130°C to produce a yellowish transparent resin without any precipitation. The pyrolysis of the resin at 350°C yielded a powder precursor for (Ba,Sr)SnO 3. Pure SrSnO 3 is found with a pseudo cubic structure, which has some deviation from the perfect cubic lattice. X-ray diffraction (XRD) indicated the formation of pseudo-cubic (Ba,Sr)SnO 3 when the barium, strontium–tin precursor was heat treated in air at 600°C or above for 2 h. The solid solution of (Ba,Sr)SnO 3 exhibited a transition from the ideal cubic structure to a pseudo cubic structure.