Dependence of optical properties on specific surface area and grain sizes in TiO2 powders

The diffuse reflectance (DR) spectra and the cathodoluminescence (CL) spectra in the range 0.34–2.10 μm and changes in the spectra after bombardment by accelerated electrons have been studied as a function of the specific surface area and the grain sizes of titanium dioxide (rutile) powders of different grades (P1, P2, P02, R10). It has been established that the diffuse reflection coefficient and the luminescence band intensity increase as the specific surface area decreases and the grain size of the powder increases. A smaller specific surface area of the powders means lesser initial flareup and subsequent “quenching” of the CL bands as a function of electron fluence. It has been shown that history-related differences between powders of different grades is a less significant factor than the specific surface area in determining the diffuse reflectance and luminescence and also the radiation resistance of the powders. __________ Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 1, pp. 73–77, January–February, 2006.