Studies on molten glass sealing in diffusion coefficient measurements using shear cell technique

To develop a shear cell technique for measuring the diffusion coefficient o f molten materials with high vapor pressure, molten silica glass was used t o seal the vapor leak from the clearance between the cell and the rotating rod. An apparatus was designed to investigate the sealing ability of severa l molten silica glasses. Using Corning 0211, 7059, and 7740 silica glasses, Ar could be sealed under 150 kPa in the 1100-1500 K temperature range. The corresponding viscosities of the molten silica glasses in the sealing temp erature range were 10(5.3)-10(3.8) Pa s. Based on the results of Ar sealing experiments, the configuration of molten glass sealing was used to seal th e As vapor leak in InxGa1-xAs diffusion coefficient measurement experiments . The As vapor leak was successfully sealed and excellent diffusion coeffic ient measurement data were obtained using the shear cell technique during m icrogravity experiments carried out on sounding rocket. (C) 2000 American I nstitute of Physics. [S0034-6748(00)04505-6].