Polyselenide formation in borosilicate glasses

Autor: Charlotte W. Schreiber, Henry D. Schreiber
Rok vydání: 1993
Předmět:
Zdroj: Journal of Non-Crystalline Solids. 155:209-220
ISSN: 0022-3093
DOI: 10.1016/0022-3093(93)91255-2
Popis: Several mechanisms are presented for the formation of polyselenide ions (Sex2−) in a reference alkali borosilicate melt. Such ions exist in selenium-containing melts as intermediates in the redox equilibrium between elemental selenium and selenide ions under relatively reducing conditions. Molecular selenium can also be reduced to polyselenide ions by iron (Fe2+) or uranium (U5+) under somewhat more oxidizing conditions in the melt. Even though polyselenides exist in low concentration in the melt, they greatly affect the resulting optical properties by imposing an amber coloration. The redox mechanism for the formation of polyselenides by the reduction of elemental selenium in glass melts is in opposition to that for the formation of polysulfides which relies on the oxidation of sulfide ions by iron, vanadium, or uranium redox couples.
Databáze: OpenAIRE