Early stage nucleation in barium disilicate glass

Published

August 1, 2020

Author(s)

Ling Cai, Randall E. Youngman, David E. Baker, Aram Rezikyan, Minghui Zhang, Bryan Wheaton, Indrajit Dutta, Bruce G. Aitken, Andrew J. Allen

Abstract

Early stage nucleation in silicate glasses is often evidenced by formation of nanosized regions that are stoichiometrically different from the surrounding matrix. The structural origin of these early stage nucleation sites is of great interest in gaining a fundamental understanding of nucleation kinetics in silicate systems. However, these regions are experimentally difficult to observe due to their small size and low volume concentration. In this study, we present an experimental study on the early stage nucleation processes of the BaO·2SiO2 (BS2) system. Extensive experimental measurements were carried out on BS2 glass samples that were heat treated between the glass transition temperature, Tg, and the crystallization temperature, Tcr. Differential scanning calorimetry (DSC), X-ray diffraction (XRD), nuclear magnetic resonance (NMR), both scanning and transmission electron microscopy (SEM and TEM), and synchrotron-based small-angle X-ray scattering (SAXS) were used to identify the structural origin of the heterogeneities formed during early stage nucleation. The data show that the initial crystallites include the stoichiometric BaSi2O5 phase and other higher Ba/Si ratio phases. Moreover, unlike that reported in the lower BaO content barium silicate or the analogous Li2O−SiO2 systems, no clear evidence is observed for liquid/liquid phase separation in the BS2 system.

Citation

Journal of Non-Crystalline Solids

Pub Type

Journals

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https://doi.org/10.1016/j.jnoncrysol.2020.120330

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Keywords

barium disilicate glass, crystallite nucleation, materials characterization

Citation

Cai, L. , Youngman, R. , Baker, D. , Rezikyan, A. , Zhang, M. , Wheaton, B. , Dutta, I. , Aitken, B. and Allen, A. (2020), Early stage nucleation in barium disilicate glass, Journal of Non-Crystalline Solids, [online], https://doi.org/10.1016/j.jnoncrysol.2020.120330, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=928993 (Accessed December 14, 2024)