X-ray absorption spectral analyses by theoretical calculations for TiO2 and Ni-doped TiO2 thin films on glass plates.

Ni L- and Ti L-edge as well as Ti K-edge X-ray absorption experiments for TiO2 thin films and Ni-doped TiO2 thin films coated on glass plates were performed using synchrotron radiation to investigate the structures around Ni and Ti ions in the films. The obtained spectra were compared with the results of theoretical calculations. It has consequently been found that the spectral features were affected by a change in the oxidizing form of Ni ions due to hydrogen reduction, by the charge variation and/or slight orbital splitting of Ti ions, and by the magnitude of the interaction between the center Ti ion and neighboring Ti ions.

Experimental technique for radiative-process-resolved X-ray absorption spectroscopy at the inner-shell excitation thresholds.

Partial-fluorescence-yield (PFY) x-ray absorption measurements, rising the optimized window widths of position sensitive detectors in wave-length dispersive x-ray spectrometers, have been applied for radiative process-resolved (RPR) x-ray absorption spectroscopy. We have measured PFY-absorption spectra of graphite and diamond at the C K threshold and of h-BN and c-BN at the B K threshold. Resonant elastic x-ray scattering was observed in graphite and h-BN on their PFY-absorption spectra, and excitonic x-ray scattering was observed in diamond and c-BN. These results show that PFY-absorption measurements for RPR x-ray absorption spectroscopy can provide the information about the electronic structures and the radiative-decay process in inner-shell excitation.