Relaxation Effects in Glassy Selenium.
Abstract
Thermal relaxation phenomena were measured in samples of both melt-quenched and evaporated selenium. On the basis of earlier studies, the two methods of preparation produced samples with polymeric chain concentrations of 30-50% and 0% respectively; the rest of the material was in the form of 8 member rings. The relaxation peak occurred between 320 and 330K, and had an activation energy of approximately 22.5 kcal/mole for the melt-quenched sample. A decrease of 1K in the glass relaxation temperature and 0.5 kcal/(gm atom) in the activation energy was observed in samples which had been initially evaporated. No change was observed as a result of melting and quenching these evaporated samples. Two consequences of this postulate are that the selenium analogue to the sulfur polymerization transition must occur well below room temperature if it exists, and therefore, that the equilibrium ring chain ratio can be smoothly extrapolated down to room temperature from the published high temperature data.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 1975
- Accession Number
- ADA006977
Entities
People
- R. B. Stephens
Organizations
- Harvard University