Thermal behavior in Se-Te chalcogenide system: Interplay of thermodynamics and kinetics
- Faculty of Chemical Technology, Department of Physical Chemistry, University of Pardubice, Studentska 573, 532 10 Pardubice (Czech Republic)
Heat capacity measurements were performed for Se, Se{sub 90}Te{sub 10}, Se{sub 80}Te{sub 20}, and Se{sub 70}Te{sub 30} materials in the 230–630 K temperature range. Both glassy and crystalline C{sub p} dependences were found to be identical within the experimental error. The compositional dependence of the N-type undercooled liquid C{sub p} evolution was explained on the basis of free-volume theory; vibrational and chemical contributions to heat capacity were found to be roughly similar for all Se-Te compositions. The thermal behavior in the Se-Te chalcogenide system was thoroughly studied: glass transition, cold crystallization, and melting were investigated in dependence on composition and various experimental conditions (heating rate, particle size, and pre-nucleation period). The kinetics of the structural relaxation and crystallization processes are described in terms of the Tool-Narayanaswamy-Moynihan and Johnson-Mehl-Avrami models. The complexity of these processes is thoroughly discussed with regard to the compositionally determined changes of molecular structures. The discussion is conducted in terms of the mutual interplay between the thermodynamics and kinetics in this system.
- OSTI ID:
- 22413306
- Journal Information:
- Journal of Chemical Physics, Vol. 141, Issue 22; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-9606
- Country of Publication:
- United States
- Language:
- English
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