Raman scattering from hydrogen and deuterium dissolved in silica as a function of pressure

Abstract

Studies of the Raman scattering from hydrogen and deuterium dissolved in vitreous silica at 90 °C and at pressures from 66 to 849 atm have been performed. The Raman spectra are interpreted to give information about the physics and thermodynamics of dissolution. In particular it is shown that: (1) hydrogen dissolves as a molecule, (2) the dissolved molecules occupy confining interstices and bind only weakly to the silica, and (3) the solubility saturates at higher pressures when the available interstices become filled. The results are explicable using classical thermodynamics and a physical rather than chemical model for dissolution.