SMALL-ANGLE X-RAY-SCATTERING STUDIES OF NANOPHASE TIO2 THIN-FILMS

Nanosized TiO2 thin films on glass substrate of thickness ranging from 1 to 7 mu m were prepared using sol-gel and P25 paste procedure [1 - 6]. SAXS measurements at the ELETTRA synchrotron (Italy, Trieste) reve aled that TiO2 crystallite size increased in 'average particle radii' values [R] from 2.5 to 10.0 nm with annealing temperature from room te mperature to 900 degrees C. Thermal annealing was performed in atmosph eres of H-2, O-2 and N-2 for sol-gel and in O-2 and H-2 for P25 prepar ed samples. The 'average particle radii' values [R] varied differently between the two different types of preparation. The specific surface area of these films was also determined and generally varied from 10(6 ) to 10(8) cm(-1). (C) 1998 Elsevier Science S.A. All rights reserved.