Optical and acoustical phonon properties of BeTe
| Autor: | Veit Wagner, T. Gerhard, G. Landwehr, Th. Litz, U. Küster, Jean Geurts, F. Fischer, H.-J. Lugauer, R. Kruse, Ch. Becker, S. Gundel, Andreas Waag |
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| Rok vydání: | 1998 |
| Předmět: |
Condensed matter physics
Phonon business.industry Chemistry Superlattice Dielectric Condensed Matter Physics Inorganic Chemistry Condensed Matter::Materials Science symbols.namesake Tight binding Optics Chemical bond Molecular vibration Materials Chemistry symbols Local-density approximation business Raman spectroscopy |
| Zdroj: | Scopus-Elsevier |
| ISSN: | 0022-0248 |
| Popis: | We present an investigation of the vibrational properties, the elastic constant c11 and the infrared dielectric constant e∞ of BeTe. For this purpose we applied far-infrared reflectance and Raman spectroscopy to single BeTe layers and BeTe/ZnSe superlattices. The experimental data are used to access the bond ionicity in the framework of an empirical tight binding approach. A low bond polarity of 0.61 is determined for BeTe, which corresponds to a high lattice stability. Furthermore, the elastic constant c11 is determined as to be 8.9 ± 0.9.1010 N/m2 from the frequency positions of folded acoustic phonon (FAP) modes in BeTe/ZnSe superlattices. The experimental results are correlated to data obtained by first-principles local density approximation (LDA) calculations. |
| Databáze: | OpenAIRE |
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