Structural relaxation in Se-rich As–Se glasses

Enthalpic structural relaxation in the AsySe(100-y) glassy system was studied by means of differential scanning calorimetry (DSC). Glasses in the compositional range 0 ≤ y ≤ 15 were examined. Based on the curve-fitting results, the description of relaxation behavior was obtained in terms of the Tool–Narayanaswamy–Moynihan model. These results were further confirmed by a novel simulation-comparative non-fitting method. Evolution of TNM parameters with changing arsenic content was interpreted in terms of joint movements of occasionally linked Se polymeric chains continuously transiting towards rather independent positional changes within inter-linked segments or clusters. The interpretation represents a novel approach associating a phenomenological description with factual changes in the molecular structure of the material.