Optical property degradation of titanium dioxide micro- and nanopowders under irradiation

Diffuse reflection spectra and absorption spectra of titanium dioxide (anatase) micro- and nanopowders induced by exposure to 100 keV protons and electrons were analyzed at wavelengths between 250 and 2500 nm. It is established that the radiation stability of the nanopowders is higher than the micropowders in the absorption region λ > 500 nm for proton and electron exposure. This effect is caused by the high concentration of radiation defects in micropowders, which is associated with defects of interstitial titanium ions (Tii, Tii), titanium vacancies (VTi⁗, VTi‴ ) and oxygen vacancies VOX.