Abstract In this work, the above room temperature heat capacity for different polymorphs of alkali and alkali-earth (i.e. Na, K, Rb, Cs, Mg, Ca) borohydrides has been measured by DSC as a function of temperature. The above room temperature measured Cp values have been compared with available extrapolated literature data, and they have been modelled as a function of temperature according to the Calphad method. The variations of Cp values for different polymorphs were studied in details and they have been related to the corresponding crystal structures, considering the mobility of the BH4− group. From the whole set of assessed thermodynamic data, possible correlations with dynamics and structural properties have been estimated.

中文翻译：

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碱金属和碱土金属硼氢化物的热容量和热力学性质

摘要 在这项工作中，使用DSC 测量了碱和碱土金属（即Na、K、Rb、Cs、Mg、Ca）硼氢化物不同多晶型物的上述室温热容与温度的关系。上述室温测得的 Cp 值已与可用的外推文献数据进行了比较，并且它们已根据 Calphad 方法建模为温度的函数。详细研究了不同多晶型物 Cp 值的变化，考虑到 BH4- 基团的迁移率，它们与相应的晶体结构有关。从整套评估的热力学数据中，估计了与动力学和结构特性的可能相关性。