Abstract
High-resolution (±0.02 cm-1) Raman and infrared transmission (ir) measurements were used to study the effect of isotopic disorder on the vibrational properties of Ge crystals. Calculations using the coherent potential and the self-consistent Born approximations were performed and compared with the experiment. The linewidth of the Raman modes is predominantly determined by the anharmonic decay of the optical phonons into lower-energy phonons, with a characteristic decay time of 6.1(±0.1) ps in natural Ge. The phonon energies of the Raman active phonon and the transverse optical ir modes at the Brillouin zone boundary (L,K,W,X-critical point) are shifted by the isotopic disorder in the material. The frequency shifts and the line broadenings are in good agreement with the theoretical calculations.
Original language | English |
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Pages (from-to) | 225-228 |
Number of pages | 4 |
Journal | Solid State Communications |
Volume | 82 |
Issue number | 4 |
DOIs | |
Publication status | Published - 1992 Apr |
Externally published | Yes |
ASJC Scopus subject areas
- Chemistry(all)
- Condensed Matter Physics
- Materials Chemistry