Chalcogenide transition temperature

Differential thermal analysis was used to delineate the glass forming regions in the Ge-Te system (Takamori et al (1970)) and the Ge-Te-As system (Savage (1971)). Myers and Felty (1967) and de Neufville (1972) have thermally determined the composition dependence of the glass transition temperature for several multicomponent chalcogenide glasses, from which they have obtained information on the chemistry and structure of these materials. 

Chalcogenide glasses from the Ge-Se system exhibit relatively low glass transition temperatures (from 41 (Se) to 340°C (Ge4oSe6o) and low activation enthalpy for flow (from 285 to 592 kJ/mol). As a consequence, they experience a time or rate dependent hardness at room temperature, especially for chalcogen-rich compositions (Fig. 3). Therefore, on one hand, these glasses offer a unique opportunity to study viscoelasticity at room-temperature, as was already mentioned earlier, but on the other hand, structural parts such as lens or fibres for applications in night visibility optical devices or in thermometry, are likely to suffer from creep deform-... 

For Ge chalcogenides such as Ge-[As)-S[Se) films, however, controversial results have been reported. For instance, in nominally the same composition of Ge27Asi3S6o, Vateva [2007) detects a volume contraction of 2%, while Knotek and Tichy [2009) report an expansion of 7.5%. Such opposite changes may arise partly from experimental artifacts. It is common, specifically in Ge chalcogenides, that the glass transition temperatures are substantially different... 

SreeramA. N., Swiler D. R., andVarshne5raA. K., Gibbs-DiMarzio equation to describe the glass transition temperature trends in multicomponent chalcogenide glasses,/. Non-Cryst. Solids, 127, 287-297 (1991). 

Tichy L. and Ticha H., Covalent bond approach to the glass transition temperature of chalcogenide glasses,/. Non-Cryst Solids, 189,141-146 (1995). 

Compared to the binary silver chalcogenide compounds, the phase transition temperature of monodisperse alloyed ternary silver chalcogenide Ag4SeS... 

Solorza-Eeria O, EUmer K, Giersig M, Alonso-Vante N (1994) Novel low-temperature synthesis of semiconducting transition metal chalcogenide electrocatalyst for multielectron charge transfer Molecular oxygen reduction. Electrochim Acta 39 1647-1653... 

---