SINTERING, CATALYTIC EFFECTS AND DEFECT CHEMISTRY IN POLYCRYSTALLINE TIN DIOXIDE

Tin oxide samples are prepared from a powder under various sintering c onditions. The morphological properties are studied. The electrical pr operties are correlated to the structural and textural characteristics , and specially in relation with the grain size. The influence of the gaseous atmosphere (humidity and various gases) on the electrical cond uctivity is investigated. Some catalytic experiments are performed in order to study the role of the analysed gas, the influence of the sint ering conditions and the nature of the electrodes. All these factors m odify the electrical conductance. The conductivity power law dependenc es are carried out in order to study the defect chemistry in tin oxide . The results are interpreted in relation to a theoretical model.