Thermal Expansion of Some Ge-Se-Te Glasses

摘要

Results of the measurement of thermal expansion coefficient (from 50 C to the softening temperature) are reported for eight glass compositions of the Ge-Se-Te system. For the (GeSe2) sub 100-2x Se sub 30-x Te sub x glasses, an increase of T sub g and of Delta alpha is seen with decreasing SeTe content. For (GeSe2) sub 23.33 Se sub 30-x Te sub x glasses, alpha, T sub g, and Delta alpha are invariant with composition. The results obtained, when examined along with those obtained for other chalcogenide glasses, show that chalcogenide glasses are not necessarily in a state of isofree volume during glass transition. Values ranging from 0.024 to 0.167 are obtained for the free volume of some chalcogenide glasses.