Properties Of Commercial And Sintered Silica Glass: Influence Of Atmospheres During Sintering And Annealing

The viscosity of synthetic silica glass made by sintering of nanoscaled particles depends on the stoichiometry which can be influenced by the H2/02 ratio during sintering. In accordance with theoretical calculations a high SiH-concentration is achieved at a very low O2 partial pressure. These silica glasses sintered in dry H2-atmosphere show the highest viscosity and a very low OH-cocentration compared to the other samples sintered in vacuum, moist H2/N2, and 02. The SiH- and SiOH- concentrations were spectroscopically detected. In comparison with natural silica glass, the viscosity of all sintered silica glasses is still significantly lower.