Proceedings of the 43rd International Field Emission Symposium
J. Phys. IV France 06 (1996) C5-135-C5-140
Field Electron Emission Spectroscopy of YBa2Cu3O6.9 Single Crystals Above and Below Superconducting Transition TemperatureS.N. Ivanov and S.I. Shkuratov
Institute of Electrophysics, Russian Academy of Sciences, 34 Komsomolskaya Str., Ekaterinburg 620049, Russia
An experimental investigation has been made of the total energy distribution of electrons emitted from the surfaces, purified by field evaporation, of YBa2Cu3O6.9 single crystals oriented in the  direction at temperatures above and below superconducting transition temperature. Field electron emission spectroscopic experiments carried out at 75 K visualized the superconducting energy gap at the Fermi-edge of the spectra. The number of electrons in the energy interval inside the gap decreases to the zero level. The double value of the superconducting energy gap for crystallographic direction  measured at temperature 75 K has the width 30 ± 5 meV.
© EDP Sciences 1996