Vibrational relaxation of lattice phonons in CS2 crystal

✍ Scribed by Leonardo Poletti; Roberto Bini; Vincenzo Schettino

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 515 KB
• Volume: 222
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(94)00347-5

✦ Synopsis

The bandwidths of four lattice modes of carbon disultide single crystal were measured by high-resolution Raman and FTIR spectroscopy in the 1 O-l 50 K temperature range. The evolution with temperature of the linewidths cannot be interpreted only on the basis of elementary relaxation mechanisms. This was ascribed to the relatively high concentration of isotopic impurities which strongly affects the phonons width. The application of a simple model, recently used for sulfur crystal, allows to identify a large temperature-independent contribution of the isotopic impurities to the line broadening which dominates the low-temperature bandwidths. The temperature-dependent line broadening is almost entirely due to three-phonon down-conversion processes below 80 K while at higher temperatures dephasing processes become dominant.

* This work was supported by the Italian Minister0 Universita e Ricerca Scientitica e Tecnologica (MURST) and Consiglio Nazionale delle Ricerche (CNR) .