Twenty-six glassy compositions, belonging to the Ge xIn 6Se 94-x and Ge xIn 12Se 88-x families of the Ge–In–Se system, were prepared from high purity constituent elements. Differential Scanning Calorimetry (DSC) measurements were carried out on these glasses. The DSC thermograms were used to determine the glass transition temperatures ( T g) for the compositions examined. The T g-composition dependence of the Ge xIn 6Se 94-x family shows a minimum in T g at a value of the average coordination number, < r>, equal to 2.4. For both families of the glasses examined, the T g-< r> dependence displays maxima at < r>=2.75 and < r>=2.83 for Ge xIn 6Se 94-x and Ge xIn 12Se 88-x families, respectively. These results are interpreted by using the Phillips model of rigidity percolation and Chemically Ordered Covalent Network (COCN) model.

Applied Physics A: Materials Science & Processing, Volume 61, Number 1 / July, 1995