X-ray photoelectron spectroscopic study and electronic structure of double-perovskites A2SmTaO6 (A= Ba, Sr, Ca)

X-ray photoelectron spectroscopy (XPS) measurements of double perovskite oxides, A(2)SmTaO(6) (A = Ba, Sr, Ca) are performed in the energy window of 0-1300 eV. The electronic structure investigations of AST have been performed using density functional theory. The calculated DOS is compared with the experimental DOS obtained by XPS. It has been observed that the Sm-f and O-2p states are hybridized in the valence band near the Fermi level. The chemical shifts of the constituent elements determined from the core-level XPS spectra deliver information on charge transfer and nature of chemical bonds. These results have been used to explain the conduction mechanism in these materials. (C) 2017 Published by Elsevier Masson SAS.