SHORT-RANGE ORDER EVOLUTION IN THE PREPARATION OF SNO2 BASED MATERIALS

The evolution of EU(3+) doped SnO2 xerogels to the cassiterite structu re observed during sintering was studied by means of EU(3+) spectrosco py, XRD and EXAFS at the Sn K-edge. EU(3+) ions adsorbed at the surfac e of colloidal particles present a broad distribution of sites, typica l of oxide glasses. With sintering at 300 degrees C, this distribution is still broadened. Crystallization is clearly observed by the three techniques with increasing sintering temperature. It is found that the addition of EU(3+) limits the crystallite growth.