Abstrakt:
Differential scanning calorimetry (DSC) measurements were used to study
enthalpic structural relaxation in selenide glasses. The examined compositions
were, apart from pure Se, the following Se(100–y)Tey (for y = 0.1, 0.2 and 0.3),
GeySe(100–y) (for y = 0.02, 0.04, 0.06, 0.08, 0.10 and 0.15) and AsySe(100–y)Tey (for y
= 0.02, 0.04, 0.06, 0.08 and 0.10). Based on the results of fitting and non-fitting
methods, relaxation behavior of these glasses was described in terms of
the Tool–Narayanaswamy–Moynihan (TNM) model. The TNM model parameters
as well as their change with respect to both increasing content of dopant in Se
matrix within each chalcogenide system and different structural units employed in
the respective systems were discussed. A unique conception was suggested,
introducing a connection between the values of TNM parameters and respective
molecular structures and their changes during structural relaxation. By such
qualitative interpretation, the main disadvantage of phenomenological models may
be, at least partially, overcome.