## Oxygen stoichiometry and the electronic structure of high-temperature superconductors

The oxygen content determines the transport properties of Ba<sub>2</sub>YCu<sub>3</sub>O<sub>7+x</sub> and EuBa<sub>2</sub>Cu<sub>3</sub>O<sub>7+x</sub>, and in particular their superconducting behavior at high temperatures. The authors studied the changes in the Ba<sub>2</sub>YCu<sub>3</sub>O<sub>7+x</sub> electronic structure which are caused by modifications in the amount of oxygen. The modifications were achieved either by thermal annealing or by exposure to white' synchrotron radiation which causes oxygen desorption, with similar results. They found that the decrease in oxygen content affects the line-shape of the upper valence band features and the relative intensity of the Cu satellite features. The lineshape changes simplify the identification of oxygen-related features in the upper valence band region. The exposure to white' synchrotron radiation of Ba<sub>2</sub>EuCu<sub>3</sub>O<sub>7+x</sub> did not produce similarly large spectral changes

Year:
1988
Keywords:
Note:
3130066
high temperature superconductivity
O stoichiometry dependence
electronic structure
transport properties
superconducting behavior
thermal annealing
line-shape
upper valence band features
relative intensity
Cu satellite features
Ba2YCu3O7+x
EuBa2Cu3O7+x
Laboratories: