Corrosion by a heavy metal oxide glass

Melts of lead bismuth gallate compositions are highly corrosive and attack on crucibles of different materials. In the present study, corrosion by a base glass (50PbO-30Bi(2)O(3)-2OGa(2)O(3) in mole fraction) melted using different crucibles and the effect on UV-VIS and IR edges were studied. By melting the base glass in platinum/2 % rhodium, gold zirconia and alumina crucibles showed less effect on the IR edge and therefore shifted the infrared edge to longer wavelength, whereas silica crucible contaminated the glass, causing a severe deterioration in the infrared and hence shifted infrared edge to much shorter wavelength. In the UV-VIS region, base glass melted in platinum/2 % rhodium crucible shifted the edge to the longest wavelength whereas silica crucible shifted the edge to shorter wavelength. The contaminants from gold, zirconia and alumina crucibles caused the UV-VIS edge of the base glass to lie between the two extremes of Pt/2 % Rh and SiO2 crucibles. The glasses melted in above mentioned crucibles were also characterized with inductively coupled plasma spectroscopy (ICP) analysis to measure the level of contamination from the crucibles. Depending upon crucible used, the colors of glasses obtained ranged from red to yellow.