The Use of Single-Crystal Rare-Gas Lattices to Study Homogeneous Lineshapes of Impurities - Sf6 in Xenon

The IR absorption spectrum of SF6 in single crystal xenon has been studied as a function of temperature. Only one trapping site is stable in single crystal xenon and the v3 linewidth for this site is dominated by homogeneous broadening throughout the entire temperature range studied (14–160 K). The v3 linewidth shows an approximate eαT dependence which is inconsistent with either elastic phonon scattering or local phonon modes independently as the dominant dephasing mechanism. The results suggest that dephasing involves both site local and bulk phonon modes with the former dominating at low temperatures and the latter at higher temperatures.