| Numéro |
J. Phys. Colloques
Volume 42, Numéro C6, Décembre 1981
International Conference on Phonon Physics
|
|
|---|---|---|
| Page(s) | C6-652 - C6-654 | |
| DOI | https://doi.org/10.1051/jphyscol:19816190 | |
International Conference on Phonon Physics
J. Phys. Colloques 42 (1981) C6-652-C6-654
DOI: 10.1051/jphyscol:19816190
1 Max-Planck-Institut für Festkörperforschung, Stuttgart, F.R.G.
2 University of Graz, Austria
J. Phys. Colloques 42 (1981) C6-652-C6-654
DOI: 10.1051/jphyscol:19816190
VOLUME AND TEMPERATURE DEPENDENCE OF THE TRANSVERSE CHARGE AND THE IONICITY OF TETRAHEDRAL SEMICONDUCTORS
D. Olego1, M. Cardona1 et P. Vogl21 Max-Planck-Institut für Festkörperforschung, Stuttgart, F.R.G.
2 University of Graz, Austria
Abstract
The transverse charge e*T and thus the ionicity of most tetrahedral semiconductors (e. g. GaAs) decreases with decreasing volume. We have measured the volume dependence of e*T in 3C-Sic and found dln e*T/dlnv = -0.67, with a sign opposite to the usual one. These results have been interpreted with pseudopotential calculations of e*T vs. volume. Semiempirical bond orbital models, (e.g. Harrison), are not able to explain this anomalous behavior of e*T. We also report the temperature dependence of e*T and interpret it with pseudopotential theory (de*T/dt = -9.0 (5) x 10 K-1.