In this work, we explore the thermodynamic evolution in a melt-quenched metal–organic framework glass, formed from ZIF-62 upon heating to the melting point (T_m), and subsequent enthalpy relaxation. The temperature dependence of the difference in Gibbs free energy between the liquid and crystal states of ZIF-62 in the temperature range from the glass transition temperature (T_g) to T_m is found to be weaker than those of other types of glasses, e.g., metallic glasses. Additionally, we find that the stretched exponent of the enthalpy relaxation function in the glass varies significantly (β = 0.44–0.76) upon changing the extent of sub-T_g annealing, compared to metallic and oxide glasses with similar T_gs, suggesting a high degree of structural heterogeneity. Pair distribution function results suggest no significant structural changes during the sub-T_g relaxation in ZIF-62 glass.

中文翻译：

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金属-有机骨架玻璃中的热力学特征和焓松弛†

在这项工作中，我们探索了由ZIF-62加热至熔点（T _m）和随后的焓弛豫后，由ZIF-62形成的熔融淬火金属有机框架玻璃的热力学演化。发现在从玻璃化转变温度（T _g）至T _m的温度范围内，ZIF-62的液晶态与晶体态之间吉布斯自由能之差的温度依赖性比其他类型的玻璃弱（例如，，金属眼镜。此外，我们发现，改变亚T _g的程度，玻璃中焓弛豫函数的拉伸指数显着变化（β = 0.44–0.76）。与具有相似T _g s的金属和氧化物玻璃相比，退火表明结构高度异质。对分布函数的结果表明所述子期间没有显著结构变化Ť_克在ZIF-62玻璃松弛。