Topological Phases of Chalcogenide Glasses Encoded in the Melt Dynamics (Phys. Status Solidi B 6/2018)

As a melt cools to form a glass, could it be that melt dynamics encode the glass topological phases? This question is addressed by Punit Boolchand and co-workers in article no. 1800027. Select Raman scattering and calorimetric experiments, on specially homogenized binary Ge_xSe_100–x and Ge_xS_100–x glasses show that, in each chalcogenide glass system, the melt fragility index (m) displays a minimum (m < 20) in the 20% < x < 26% compositional range – the fragility window. Enthalpy of relaxation (ΔH_nr) at the glass transition temperature (T_g) in each glass system displays a square-well-like behavior with ΔH_nr ~ 0, in the same 20% < x < 26% composition range – the reversibility window. The correlation between fragility and reversibility windows suggests that melt dynamics determine the glass topological phases, a feature that could be generic in glass science.

This article is part of the special section on “Amorphous and Nanostructured Chalcogenides”, comprising 5 articles in this issue of pss(b) and guest-edited by Mihai Popescu.