Jm. Mariot et al., ELECTRONIC-STRUCTURE OF YBCO AS A FUNCTION OF OXYGEN-CONTENT - AN X-RAY-EMISSION APPROACH, Physica. C, Superconductivity, 235, 1994, pp. 1055-1056
The Cu 3d states in a series a YBa2Cu3O7-x thin film samples with vary
ing oxygen content have been investigated by x-ray emission spectrosco
py. A decrease in the intensity of the emission attributable to the dp
sigma states is observed when the oxygen concentration is increased.
This suggests that charge is transferred mainly to the Cu atoms in the
chains upon doping.