Electronic structure of the La1 + xBa2 − xCu3O7 + δ system studied by photoelectron spectroscopy

Abstract Photoemission experiments utilizing synchrotron radiation have been carried out on the high temperature superconductor La 1.075 Ba 1.925 Cu 3 O 7.0 . The valence band spectra show similar spectral features as those of YBa 2 Cu 3 O 6.9 , even though large differences in relative peak intensities are observed. Oxygen-related states are identified by scanning the photon energy through the O2 s → O2 p absorption edge. The stability of the sample surface, and changes in the valence band spectra after annealing in ultrahigh vacuum are also briefly discussed.