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Journal Articles Journal of Non-Crystalline Solids Year : 2016

Structural studies of Bi2O3-Nb2O5-TeO2 glasses

Abstract

Bi2O3-Nb2O5-TeO2 glasses show unusual annealing behavior with appearance of spherulites within the matrix glass structure for the Bi0.5Nb0.5Te3O8 composition. The textures resemble those found previously among polyamorphic Al2O3-Y2O3 glasses containing metastably co-existing high- and low-density phases produced during quenching. However the spherulites produced within the Bi2O3-Nb2O5-TeO2 glass are crystalline and can be identified as an "anti-glass" phase related to beta-Bi2Te4O11. We used high energy synchrotron X-ray diffraction data to study structures of binary and ternary glasses quenched from liquids within the Bi2O3-Nb2O5-TeO2 system. These reveal a glassy network based on interconnected TeO4 and TeO3 units that is related to TeO2 crystalline materials but with larger Te ... Te separations due to the presence of TeO3 groups and non-bridging oxygens linked to modifier (Bi3+, Nb5+) cations. Analysis of the viscosity-temperature relations indicates that the glass-forming liquids are "fragile" and there is no evidence for a LLPT occurring in the supercooled liquid. The glasses obtained by quenching likely correspond to a high-density amorphous (HDA) state. Subsequent annealing above T-g shows mainly evidence for direct crystallization of the "anti-glass" tellurite phase. However, some evidence may exist for simultaneous formation of nanoscale amorphous spherulites that could correspond to the LDA polyamorph. The quenching and annealing behavior of Bi2O3-Nb2O5-TeO2 supercooled liquids and glasses is compared with similar materials in the Al2O3-Y2O3 systeth. (C) 2016 Elsevier B.V. All rights reserved.

Dates and versions

hal-01414181 , version 1 (12-12-2016)

Identifiers

Cite

Martin C. Wilding, Gaëlle Delaizir, Chris J. Benmore, Yann Gueguen, Morgane Dolhen, et al.. Structural studies of Bi2O3-Nb2O5-TeO2 glasses. Journal of Non-Crystalline Solids, 2016, 451, pp.68--76. ⟨10.1016/j.jnoncrysol.2016.07.004⟩. ⟨hal-01414181⟩
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