Influence of temperature on elementary excitations in solid oxygen by Raman studies

Detailed Raman investigations on gaseous, liquid, and solid oxygen in its α, β, and γ phases were made. Some new features observed in the spectra are a temperature dependent splitting of the vibrational line in γ-O2 and a vibron–phonon combination in α- and β-O2. In the low energy range we measured the librational modes; one of them shows a characteristic soft mode behavior near the α–β phase transition. The influence of temperature on the librational linewidth is explained in terms of the anharmonic interaction. These data give new information about the assignment of some of the modes.