MECHANISM OF GASEOUS PERMEATION THROUGH GLASS, SINGLE-CRYSTAL SILICON, AND GERMANIUM;AND STRESS-ENHANCED GASEOUS PERMEATION THROUGH ALUMINA BODIES

摘要

This study consists of two parts. The first part is a development of a more fundamental and quantitative understanding of the transport of noble gas atoms through glasses and single-crystal Si and Ge. Literature pertinent to gaseous permeation through these materials is reviewed with respect to experimental data and explanations for the observed permeations. A series of equations for the permeation coeffi¬cient is developed in terms of the solubility coefficient and diffusion coefficient. The theory is further extended for Si and Ge to include calculation of the activation energy for diffusion and solution. From this resulting quantitative theory it is possible to explain the relation¬ship of glass modifiers to permeability, and the increase in density with increasing amounts of glass modifiers up to about 10 mol percent, and to identify the forces probably responsible for the observed activa¬tion energies for diffusion and solution.