STRUCTURAL-ANALYSIS OF MIXED TIN OXIDES PRODUCED BY THE SOL-GEL METHOD

Mixed oxides SiO2/SnO2 with 80/20 nominal weight composition have been obtained by the sol-gel method with different precursors. X-ray diffraction and low temperature transmission Mossbauer spectroscopy have been used to follow the structural evolution of the samples after treatments in the temperature range RT-1050 degrees C. The main results are that changes in the precursor nature and gel preparation affect the Sn(IV) homogeneity in the SiO2 matrix and that the use of Sn-alkoxides increases the content of residual carbon which promotes reduction of Sn(IV) at intermediate temperatures.