IN-SITU CHARACTERIZATION OF DOPING-EFFECT ON ELECTRONIC-STRUCTURE OF EPITAXIAL-FILMS OF INFINITE-LAYER SRCUO2

Change of electronic structure of infinite-layer SrCuO2 epitaxial film with both hole- and electron-doping has been studied by in-situ photo emission spectroscopy. In both of the cases, semiconducting gap in the vicinity of the stoichiometric compound has been vanished by ''light- doping.'' By further introductions of carriers, monotonous shifts of c ore-binding energies have been observed; the shift toward lower bindin g-energy region by the hole-doping, and that toward higher side by the electron-doping, Total amount of the shift over the whole range of th e doping was much smaller than the semiconducting gap. For the metalli c regions, comparison between the energy-shift observed and that expec ted by a calculation under local-density-approximation is discussed.