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Updated: Dec 3, 2025
Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses
Published on: June 7, 2018
Chemical and Structural Variety in Sodium Thioarsenate Glasses Studied by Neutron Diffraction and Supported by
Mohammad Kassem1, Tinehinane Bounazef1, Daniele Fontanari1
1Laboratoire de Physico-Chimie de l'Atmosphère, Université du Littoral Côte d'Opale, 59140 Dunkerque, France.
Abstract:
Sodium-conducting sulfide glasses are promising materials for the next generation of solid-state batteries. Deep insight into the glass structure is required to ensure a functional design and tailoring of vitreous alloys for energy applications. Using pulsed neutron diffraction supported by first-principles molecular dynamics, we show a structural diversity of Na2S-As2S3 sodium thioarsenate glasses, consisting of long corner-sharing (CS) pyramidal chains CS-(AsSS2/2), small AsS rings (p + q ≤ 11), mixed corner- and edge-sharing oligomers, edge-sharing (ES) dimers ES-As2S4, and isolated (ISO) pyramids ISO-AsS3, entirely or partially connected by sodium species. Polysulfide S-S bridges and structural units with homopolar As-As bonds complete the glass structure, which is basically different from structural motifs predicted by the equilibrium phase diagram. In contrast to superionic silver and sodium sulfide glasses, characterized by a significant population of isolated sulfur species Siso (0.20 < Siso/Stot < 0.28), that is, sulfur connected to only mobile cations M+ with a usual M/Siso stoichiometry of 2, poorly conducting Na2S-As2S3 alloys exhibit a modest Siso fraction of 6.2%.
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