冰晶石的温致相变及熔盐微结构的定量解析

Thermal Phase Transformation and Quantitative Analysis of Cryolite Molten Salt

本工作制备了NaF-AlF_(3)二元系中分子比CR=3的冰晶石晶体,构建了一系列铝氟团簇结构模型,运用显微共焦Raman光谱检测技术与第一性原理理论计算相结合,观察和研究了冰晶石从单斜-立方-六方晶系的温致相变过程,并对熔盐实验拉曼光谱进行散射截面校正、分峰解谱,分析了NaF-AlF_(3)二元体系中AlF_(4)^(-)(622-628 cm^(-1))、AlF_(5)^(2-)(555-560 cm^(-1))、AlF_(6)^(3-)(510~515 cm^(-1))等阴离子团簇的Raman特征峰位置,定量解析了冰晶石熔盐微结构中的多种阴离子团簇,其摩尔百分含量分别为AlF_(4)^(-)(2.7%)、AlF_(5)^(2-)(25.8%)、AlF_(6)^(3-)(40.4%)、F^(-)(31.3%)。

In this work,cryolite crystals with a molecular ratio of CR=3 in the NaF-AlF_(3) binary system were prepared,and a series of aluminum-fluorine cluster structure models were constructed.The micro-confocal Raman spectroscopy detection technology was combined with first-principle theoretical calculations.The author observed and studied the temperature-induced phase transition process of cryolite,and analyzed the Raman characteristic peak positions of anionic clusters such as AlF_(4)^(-)(622-628 cm^(-1)),AlF_(5)^(2-)(555-560 cm^(-1)),AlF_(6)^(3-)(510-515 cm^(-1)).As for the cryolite molten salt system,by correcting the scattering cross section and splitting the peak of the molten salt experimental Raman spectrum,quantitatively analyzed the microstructure of cryolite molten salt.In the cryolite molten salt,the various anionic clusters have molar percentages of AlF_(4)^(-)(2.7%),AlF_(5)^(2-)(25.8%),AlF_(6)^(3-)(40.4%),F^(-)(31.3%).