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
1988
165
272
Wisconsin Univ., Madison, WI, USA
3130066