Local and electronic structure of Sr1-Gd TiO3 probed by X-ray absorption spectroscopy

Gadolinium-doped strontium titanate (Sr1-xGdxTiO3) is a typical perovskite structure material which has been studied due their thermomechanical, termoelectrical and electrochemical properties. In this study, local electronic of Sr1-xGdxTiO3 samples were analyzed through X-ray absorption spectroscopy measurements. The results obtained with the adjustment extended fine (EXAFS) spectra at Sr K-edge show that crystallographic model Pm-3m space group consistent around atoms, as expected. This same analysis also reveals an increasing Debye-Waller function Gd content in some shells, associated disorder induced by vacancies to heterovalent incorporation. EXAFS LIII-edge for indicates regular GdO12 dodecahedra without displacement atoms from centrosymmetric position. A was identified shells beyond first 12 O neighbors neither cubic SrTiO3 nor orthorhombic GdTiO3 fits well. near edge (XANES) spectrum Ti LIII,II-edges shows asymmetric peak because splitting between eg orbitals 3d band sample. addition cause enlargement split small Several features XANES are affected increase concentration. According our calculated projected density states, these transitions related reduction number unoccupied 2p - states caused band. Moreover, dependence hybridization 5d4f6s states.