Abstract

In this paper, we select the values of the molecular constants and calculate the thermodynamic functions for YI₃ and Y₂I₆ based on a critical analysis of experimental and theoretical data on the structure and vibration frequencies of the monomeric and dimeric forms of yttrium triiodide molecules. Using the literature data on the ratio of the partial pressures of dimeric and monomeric molecules and the third law of thermodynamics, we determine the enthalpy of YI₃(cr., l) + YI₃(g) = Y₂I₆(g) reaction and calculate the composition of the yttrium iodide vapor in the temperature range of 800–961 K, for which there are literature data on the total pressure. In the considered temperature range, P_d/P_m pressure ratio is found to increase from 0.003 to 0.014. The partial pressures determined are used to calculate the sublimation enthalpies of yttrium triiodide in the form of monomeric and dimeric molecules and the enthalpies of formation of these molecules. The obtained values have been entered into the database of the IVTANTERMO software package.

中文翻译：

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YI 3和Y 2 I 6分子形式的三碘化钇蒸发的热力学

摘要

在本文中，我们基于对三碘化钇单体和二聚体形式的结构和振动频率的实验和理论数据的批判性分析，选择了分子常数的值并计算了YI ₃和Y ₂ I ₆的热力学函数。分子。使用有关二聚体和单体分子的分压之比和热力学第三定律的文献数据，我们确定YI ₃（cr。，l）+ YI ₃（g）= Y ₂ I ₆的焓（g）反应并计算在800–961 K温度范围内的碘化钇蒸气的组成，对此有关于总压力的文献数据。在所考虑的温度范围内，发现P _d / P _m压力比从0.003增加到0.014。确定的分压用于计算单体和二聚体分子形式的三碘化钇的升华焓和这些分子形成的焓。获得的值已输入到IVTANTERMO软件包的数据库中。