A ZBLAN glass of the following composition: 53 mol.% ZrF4, 20 mol.% BaF2, 4 mol.% LaF3,3 mol.% AIF3, 20 mol.% NaF is studied for predicting its glass forming ability (GFA). The GFA of a ZBLAN glass is evaluated by estimating the Gibbs free energy difference (ΔG) between the undercooled liquid and the corresponding equilibrium solid phases. Other GFA criteria (T_rg=T_g/T_l, T_x/T_l, γ=T_x/T_g+T_l, ΔT_xg=T_x-T_g, T_g/T_m) are also calculated. Here, the approximation for ΔG considering constant specific heat difference (ΔC_P) over a wide temperature range is calculated for a ZBLAN glass. The so-calculated ΔG is compared with the result of other heoretical approaches and experimental data. We can see from the result that the expression with the consideration of constant ΔC_P works well in the entire undercooling for ZBLAN glass forming system. So we can say that the specific heat difference is being constant in the entire undercooling for ZBLAN glass.

中文翻译：

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ZBLAN玻璃的玻璃成型能力

为了预测其玻璃形成能力（GFA），研究了以下组成的ZBLAN玻璃：53摩尔％的ZrF 4，20摩尔％的BaF 2，4摩尔％的LaF 3，3摩尔％的AIF 3，20摩尔％的NaF。通过估算过冷液体和相应的平衡固相之间的吉布斯自由能差（ΔG）来评估ZBLAN玻璃的GFA。其他GFA标准（T _rg = T _g / T _l，T _x / T _l，γ= T _x / T _g + T _l，_ΔTxg = T _x -T _g，T _g / T _m）也计算在内。在此，考虑到ΔG恒定比热差（ΔC近似_P）在宽的温度范围内被计算为一个ZBLAN玻璃。将如此计算出的ΔG与其他理论方法和实验数据的结果进行比较。我们可以从与考虑常数ΔC表达的结果看_P效果很好在ZBLAN玻璃形成系统的整个过冷。因此可以说，在ZBLAN玻璃的整个过冷过程中，比热是恒定的。