Abstract
The dissolution mechanism of YbOF in a fluoride-containing (LiF-CaF(2))(eut.) molten salt is the basis for analyzing the structure of the resulting medium and optimizing the electrolytic preparation of rare-earth Yb alloys. In this study, isothermal saturation was used to analyze solubility changes of YbOF in the (LiF-CaF(2))(eut). system. Quantum chemical and molecular dynamics ab initio methods were used to study the basic properties of the components of the (LiF-CaF(2))(eut.)-YbOF system and the microscopic structural changes during the dissolution process. In addition, structural changes in the YbOF-saturated (LiF-CaF(2))(eut.) system were analyzed by combining cryogenic-temperature Raman spectroscopy with experimental methods. The results show the solubility of YbOF increased linearly in the temperature range of 1073-1323 K. As the melting temperature exceeded 1073 K, LiF and CaF(2) gradually dissociated into Li(+), Ca(2+), and F(-). In the initial stages of YbOF dissolution (1073-1173 K), the Yb-F bond was less stable than the Yb-O bond; YbOF dissociated into YbO(+) and F(-) in this temperature range. When the temperature was increased above 1173 K, YbO(+) further dissociated into Yb(3+) and O(2-). Overall, the dissolution of YbOF did not affect the main structure of the (LiF-CaF(2))(eut.) system.