A theoretical framework for the Vogel-Fulcher-Tammann equation for covalent network glasses derived by the stochastic matrix method
A theoretical framework for the Vogel-Fulcher-Tammann equation for covalent network glasses derived by the stochastic matrix method
复制标题
随机矩阵法导出的共价网络玻璃 Vogel-Fulcher-Tammann 方程的理论框架
DOI：
10.1088/0953-8984/12/46/305
复制
发表时间：
2000
期刊：
影响因子：
--
通讯作者：
L. Dagdug
中科院分区：
文献类型：
--
作者：
L. Dagdug
一个强/脆弱的液体模式已被用来作为基础的玻璃形成液体的分类指示液体结构的温度变化的敏感性。此外，在“脆弱性”的变化已被观察到在三元系统的Ge-As-Se取决于平均配位数。近年来，利用基于随机转移矩阵的统计方法，得到了强玻璃形成液体B_2O_3的粘度方程。在这项工作中，我们找到了三种不同类型的共价网络玻璃的粘度的理论方程。为了达到这个目的，平均弛豫时间被认为是与平均跃迁概率成反比。为了找到一个表达式的转移概率，以前的结果得到的随机矩阵方法。还使用了温度导数的方法来寻找弛豫时间的函数依赖性;我们得到了一个理论表达式，该表达式预测了共价网络玻璃的“脆弱性”的变化，该变化取决于浓度（或配位数）。
A strong/fragile-liquid pattern has been used as the basis for a classification of glass-forming liquids indicating the sensitivity of the liquid structure to temperature changes. Also, variations in `fragility' have been observed in the ternary system Ge-As-Se depending on the average coordination number. In recent papers, using a statistical method based on stochastic transition matrices, an equation for the viscosity of the strong glass-forming liquid B2O3 was obtained. In this work we find a theoretical equation for the viscosity for three different types of covalent network glass. To achieve this end, the average relaxation time is taken as inversely proportional to the average transition probability. To find an expression for the transition probability, previous results obtained by the stochastic matrix method were used. The temperature derivative method for finding the functional dependence for the relaxation time was also used; we arrived at a theoretical expression that predicts a variation in `fragility' for the covalent network glasses that depends on the concentration (or coordination number).