Fe b 19 99 Combined study of KNbO 3 and KTaO 3 by different techniques of photoelectron and X - ray emission spectroscopy

The new results are presented of the experimental study of KNbO3 and KTaO3 by means of X-ray photoelectron spectroscopy, soft X-ray emission and X-ray fluorescence spectroscopy. In particular, Nb M4,5 spectra (5p 4f → 3d5/2, 3/2 transition) have been measured over a range of near-threshold excitation energies 206.5 – 240.6 eV, and Ta N3 spectra (5d 6s→ 4p3/2 transition) over 399.4 – 420.4 eV at the Beamline 8.0 of the Lawrence Berkeley National Laboratory’s Advance Light Source. These spectra were found to be strongly dependent on the excitation energy. Moreover, the O Kα X-ray emission spectra in both compounds as well as the valence-band photoelectron spectra are brought to the binding energy scale and discussed in combination. The trends in the spectra are explained on the basis of first-principles band-structure calculations, with the dipole transition matrix elements taken into account.