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 x Se 100–x and Ge x S 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 (Δ H nr ) at the glass transition temperature ( T g ) in each glass system displays a square‐well‐like behavior with Δ H 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.