RAMAN INVESTIGATION OF NANOSIZED TIO2

Nanosized TiO2 was prepared using the sol-gel procedure. The prepared powder was thermally treated up to 1000 degrees C. X-ray diffraction ( XRD) measurements showed that the starting powder and the samples obta ined after heating this powder up to 500 degrees C were mixtures of an atase, as the dominant phase, and brookite. The crystallite sizes of t he samples were estimated using the Scherrer equation. A new approach to the size determination of nanosized TiO2, by low-wavenumber Raman s cattering, was also applied. The particle sizes, determined by low-wav enumber Raman scattering, were in agreement with the crystallite sizes measured by XRD. Rutile was produced by heat treatment of the startin g powder at 850 degrees C and higher temperatures. (C) 1997 John Wiley & Sons, Ltd.