Raman spectroscopy of molecular hydrogen and deuterium dissolved in vitreous silica

Earlier Raman studies confirming the molecular dissolution of protium and Geuterium in silica have been extended to include room-temperature measurements of the vibra ional-rotational Raman bands and the temperature dependence (11-800 K) of the Q bands. Observation of the S bands provides evidence for H₂ and D₂ molecular rotation in vitreous silica. The temperature and isotope dependence of the Q-band frequency shifts are found to agree with predictions of a solubility model based on a single molecule in a small confining interstice. The origin and temperature dependence of the Q-band line shape are discussed within the context of various models which include inhomogeneous broadening, collisional broadening, and recent theories of motional narrowing.