| Numéro |
J. Phys. Colloques
Volume 50, Numéro C8, Novembre 1989
36th International Field Emission Symposium
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|---|---|---|
| Page(s) | C8-471 - C8-475 | |
| DOI | https://doi.org/10.1051/jphyscol:1989880 | |
36th International Field Emission Symposium
J. Phys. Colloques 50 (1989) C8-471-C8-475
DOI: 10.1051/jphyscol:1989880
1 Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, D-1000 Berlin 33, F.R.G.
2 Custom Probes Unlimited, Box 3938, Gaithersburg, MD 20878, U.S.A.
J. Phys. Colloques 50 (1989) C8-471-C8-475
DOI: 10.1051/jphyscol:1989880
INTERFACE PHENOMENA IN THE FIELD ION AND FIELD ELECTRON ENERGY SPECTROSCOPY OF HIGH-Tc SUPERCONDUCTORS
N. ERNST1, G. BOZDECH1, W.A. SCHMIDT1, M. NASCHITZKI1 et A.J. MELMED21 Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, D-1000 Berlin 33, F.R.G.
2 Custom Probes Unlimited, Box 3938, Gaithersburg, MD 20878, U.S.A.
Abstract
Retarding potential analyses of ions, Ar+ and D2+, and electrons field emitted from RBa2Cu3O7-x (R = Eu, Gd, Y) tips have been carried out for surface conditions characterized by field evaporation (FEV) and field ion imaging (FIM). Energy distributions of ions and electrons, taken between 20 and 78 K, are shifted to values ranging between 1 and 19 eV above and below EF, suggesting the presence of an insulating layer. Controlled FEV, applied to decrease the thickness of this "dead" layer, leads to decreasing energy shifts. An upper limit of about 7 eV for the band gap in the insulating layer was estimated from combined field-ion and field-electron energy distribution measurements.