Electronic structure of layered ferroelectric high-k titanate Pr2Ti2O7

The spectroscopic parameters and electronic structure of binary titanate Pr2Ti2O7 have been studied by IR-, Raman and X-ray photoelectron spectroscopy (XPS) for the powder sample prepared by solid state synthesis. The spectral features of valence band and all constituent element core levels have been considered. The Auger parameters of titanium and oxygen in Pr2Ti2O7 have been determined as alpha(Ti)=872.8 and alpha(O)=1042.3 eV. Variations of cation-anion bond ionicity have been discussed using binding energy differences Delta(Ti)=(BE O 1s-BE Ti 2p(3/2))=71.6 eV and Delta(Pr)= BE(Pr 3d(5/2))-BE(O 1s)=403.8 eV as key parameters in comparison with those of other titanium- and praseodymium-bearing oxides. (C) 2012 Elsevier Inc. All rights reserved.