title: Mercury Sulfide Dimorphism in Thioarsenate Glasses.
abstract: Crystalline mercury sulfide exists in two drastically different polymorphic forms in different domains of the P,T-diagram: red chain-like insulator α-HgS, stable below 344 °C, and black tetrahedral narrow-band semiconductor β-HgS, stable at higher temperatures. Using pulsed neutron and high-energy X-ray diffraction, we show that these two mercury bonding patterns are present simultaneously in mercury thioarsenate glasses HgS-As2S3. The population and interconnectivity of chain-like and tetrahedral dimorphous forms determine both the structural features and fundamental glass properties (thermal, electronic, etc.). DFT simulations of mercury species and RMC modeling of high-resolution diffraction data provide additional details on local Hg environment and connectivity implying the (HgS2/2)m oligomeric chains (1 ≤ m ≤ 6) are acting as a network former while the HgS4/4-related mixed agglomerated units behave as a modifier.
authors.affiliation: Université du Littoral Côte d'Opale , LPCA, EA CNRS 4493, F-59140 Dunkerque, France.
authors.forename: M
authors.initials: M
authors.lastname: Kassem
authors.affiliation: Université du Littoral Côte d'Opale , LPCA, EA CNRS 4493, F-59140 Dunkerque, France.
authors.forename: A
authors.initials: A
authors.lastname: Sokolov
authors.affiliation: Université du Littoral Côte d'Opale , LPCA, EA CNRS 4493, F-59140 Dunkerque, France.
authors.forename: A
authors.initials: A
authors.lastname: Cuisset
authors.affiliation: Faculty of Science, Yamagata University , Yamagata 990-8560, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Usuki
authors.affiliation: Université du Littoral Côte d'Opale , LPCA, EA CNRS 4493, F-59140 Dunkerque, France.
authors.forename: S
authors.initials: S
authors.lastname: Khaoulani
authors.affiliation: Université du Littoral Côte d'Opale , LPCA, EA CNRS 4493, F-59140 Dunkerque, France.
authors.forename: P
authors.initials: P
authors.lastname: Masselin
authors.affiliation: Sciences Chimiques de Rennes, UMR CNRS 6226, eq Verres et Céramiques, Université de Rennes I , F-35042 Rennes, France.
authors.forename: D
authors.initials: D
authors.lastname: Le Coq
authors.affiliation: Neutron Scattering Science Directorate, Oak Ridge National Laboratory , 1 Bethel Valley Road, Oak Ridge, Tennessee 37831-6475, United States.
authors.forename: J C
authors.initials: JC
authors.lastname: Neuefeind
authors.affiliation: Neutron Scattering Science Directorate, Oak Ridge National Laboratory , 1 Bethel Valley Road, Oak Ridge, Tennessee 37831-6475, United States.
authors.forename: M
authors.initials: M
authors.lastname: Feygenson
authors.affiliation: ISIS Facility, Rutherford Appleton Laboratory , Chilton, Didcot, OX11 0QX, U.K.
authors.forename: A C
authors.initials: AC
authors.lastname: Hannon
authors.affiliation: X-ray Science Division, Argonne National Laboratory , Argonne, Illinois 60439, United States.
authors.forename: C J
authors.initials: CJ
authors.lastname: Benmore
authors.affiliation: Université du Littoral Côte d'Opale , LPCA, EA CNRS 4493, F-59140 Dunkerque, France.
authors.forename: E
authors.initials: E
authors.lastname: Bychkov