Helium Migration in TiO2-SiO2 Glasses |
| |
Authors: | J. E. SHELBY |
| |
Affiliation: | Physical Research Division, Sandia Laboratories, Livermore, California 94550 |
| |
Abstract: | Helium permeability, diffusivity, and solubility were measured for a series of TiO2-SiO2 glasses containing up to 10.3 mol% TiO2. The activation energies for helium permeation and diffusion decrease with increasing TiO2 concentration. The enthalpy of solution is independent of composition, as are the infinite-temperature values for the permeability, diffusivity, and solubility. It is concluded that the observed changes in activation energies result from changes in the strain energy necessary to distort the R-O-R'bond. The average diffusional jump distance appears to be essentially independent of composition, as would be expected from the small changes observed in the molar volume as TiO2 replaces SiO2 in these glasses. |
| |
Keywords: | |
|
|