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The kinetics of the glass transition and physical aging in germanium selenide glasses
- Source :
- Journal of Non-Crystalline Solids. 368:63-70
- Publication Year :
- 2013
- Publisher :
- Elsevier BV, 2013.
-
Abstract
- The kinetics associated with the glass transition is investigated using differential scanning calorimetry (DSC) for germanium selenide glasses with Ge content ranging from 0 to 30 at.% and average coordination numbers ranging from 2.0 to 2.6. As Ge content increases, the glass transition region broadens and the step change in heat capacity at T g decreases. As a result of physical aging, enthalpy overshoots are observed in DSC heating scans and the corresponding change in enthalpy can be calculated as a function of aging time. The change in enthalpy linearly increases with the logarithm of aging time and then levels off at an equilibrium value that increases with decreasing aging temperature. The time required to reach equilibrium increases with decreasing aging temperature and, at a given distance from T g , the time increases with decreasing germanium content. The results indicate that all samples show expected physical aging behavior, and no evidence is found for a Boolchand intermediate phase characterized by high stability and absence of physical aging.
- Subjects :
- Materials science
Kinetics
Enthalpy
Thermodynamics
chemistry.chemical_element
Germanium
Condensed Matter Physics
Heat capacity
Electronic, Optical and Magnetic Materials
chemistry.chemical_compound
Differential scanning calorimetry
Germanium selenide
chemistry
Phase (matter)
Materials Chemistry
Ceramics and Composites
Glass transition
Subjects
Details
- ISSN :
- 00223093
- Volume :
- 368
- Database :
- OpenAIRE
- Journal :
- Journal of Non-Crystalline Solids
- Accession number :
- edsair.doi...........887cc8b6821e29084e6b789a4ae0688a