Crystallization of a highly viscous multicomponent silicate glass: Rigidity percolation and evidence of structural heterogeneity

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• 作者：Shujiang Liu^a ; ^{lsj-24@163.com" class="auth_mail" title="E-mail the corresponding author} ; Yang Kong^a ; Haizheng Tao^b ; ^{thz@whut.edu.cn" class="auth_mail" title="E-mail the corresponding author} ; Yuanhua Sang^c
• 关键词：Silicate glass ; Crystallization ; Percolation theory ; Mg2+ ion coordination ; Structural heterogeneity
• 刊名：Journal of the European Ceramic Society
• 出版年：2017
• 出版时间：February 2017
• 年：2017
• 卷：37
• 期：2
• 页码：715-720
• 全文大小：1433 K

文摘

A magnesium bearing multicomponent silicate glass was annealed at the temperature slightly above glass transition temperature (T_g) for various periods of time. The crystalline phase of fluorophlogopite with the chemical formula of NaMg₃AlSi₃O₁₀F₂ is precipitated in the floppy regions, which leads to the formation of a core-shell structure. Considering that there exists only four- or six-fold coordinated Mg²⁺ in the studied glass, the fraction of four-fold coordinated Mg²⁺ is determined by comparing the maximum size of the crystallite and the floppy region according to the percolation theory. In addition, a striking phenomenon of endotherm above glass transition in heat capacity (C_p) curve is observed for the first time when prolonging the annealing time, which is ascribed to the amorphous heterogeneous structure surrounding the crystallites.