Complex dynamics in nanoscale phase separated supercooled liquids

Autor: S. Cazzato, A. Chrissanthopoulos, M. Micoulaut, T. Scopigno, S. N. Yannopoulos
Jazyk: angličtina
Rok vydání: 2020
Předmět:
Zdroj: Physical Review Research, Vol 2, Iss 3, p 032007 (2020)
Druh dokumentu: article
ISSN: 2643-1564
DOI: 10.1103/PhysRevResearch.2.032007
Popis: The relaxation properties of supercooled As_{x}S_{100−x} liquids are investigated using a combination of infrared photon correlation spectroscopy and topological constraint theory. Results reveal two channels of relaxation for sulfur-rich compositions that manifest by an unusual profile in the density-density autocorrelation function involving two typical timescales. This indicates a reduced temperature-dependent dynamics for one of the channels associated with a sulfur-rich segregated nanoscale phase that furthermore displays a low liquid fragility. Conversely, the dynamics of the emerging cross-linked As-S network is associated with a growth of the glass transition temperature with As content. These results can be quantitatively understood from topological constraint theory applied to a phase separated network for which a dedicated constraint enumeration must be achieved. The vanishing of this peculiar behavior occurs close to the reported isostatic reversibility window observed at the glass transition.
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