EXAFS measurements, from the In K edge, on Ge23.33Se64.67In12 glass, have been performed. For this glass, it is found that In is only coordinated with Se atoms. By complementing the EXAFS results obtained from the fitting procedure followed in this work with the earlier reported DSC results obtained on this system, it is concluded that in this glass, the coordination number of In is equal to three. Moreover, this approach of coupling EXAFS with DSC results allows one to calibrate the Γ factor for systems which lack a reference material, or systems for which an ab initio calculation cannot be performed, as in our case.
The values of the thermal heat-capacity changes at the glass transition temperature Tg (ΔCp=Cpl−Cpg) and the values of the apparent activation energy Δh* of the sub Tg relaxation process are determined for GexTe1−x (0.15x0.20) vitreous alloys by means of differential scanning calorimetry investigations. The values of Δh* are then used to determine the values of the fragility index, m. The comparison of these new data to those already obtained on the GexSe1−x vitreous system leads to conclude that both systems exhibit strong thermodynamic character. The stronger thermodynamic character is reached at the Phillips–Thorpe's floppy-to-rigid transition. On the other hand, we find that GexTe1−x exhibits a kinetically fragile character which decreases as the amount of Ge increases in the alloy.