Energy-loss structure in core-level photoemission satellites of SrTiO3, SrTiO3:La, and SrTiO3:Nb

The core-level x-ray photoemission spectroscopy (XPS) satellites of single-crystalline SrTiO3, SrTiO3:La, and SrTiO3:Nb in situ fractured in ultrahigh vacuum were compared with the electron-energy-toss spectrum and theoretical electron-energy-loss :functions from first-principles electronic structure calculations. Experimental core-level XPS satellites of O 1s can be represented by peaks positioned at 6.1, 11.7, 14.2, 17.2, 19.7, 27.4, and 30.6 eV. The prominent features of theoretical electron-energy-loss functions agreed with those in the experimental satellites except the peaks around 20 eV.