【摘要】 本文利用第一性原理分子动力学结合Voronoi细分法，研究了NaF-AlF₃-Al₂O₃-CaF₂/LiF/KF体系的微观结构、自扩散系数、电子性质和拉曼光谱。结果表明，Na⁺、Ca²⁺、Li⁺和K⁺主要以游离态形式存在，Al³⁺、F^-和O^2-形成了络合离子团。Al-F络合离子团由[AlF₆]^3-、[AlF₅]^2-和[AlF₄]^-组成，Al-O-F络合离子团通过O^2-替换Al-F络合离子团中的F^-形成。Al-F和Al-O离子对的平均距离均为1.725?。在含KF体系中，Al-F离子对的配位数高于其它体系，而Al-O离子对的配位数低于其它体系。Na⁺、Ca²⁺、Li⁺和K⁺具有较强的扩散能力，而Al³⁺和O^2-的扩散能力相对较弱，F^-的扩散性略强于Al³⁺。在含LiF和KF的体系中，Al-F键表现出更高的稳定性，而Al-O键在含LiF的体系中更加稳定。更多还原

【Abstract】 In this paper, the microstructure, self-diffusion coefficient, electronic properties and Raman spectra of NaF-AlF₃-Al₂O₃-CaF₂/LiF/KF system were studied by First-Principles molecular dynamics combined with Voronoi tessellation method. The results show that Na⁺, Ca²⁺, Li⁺ and K⁺ mainly exist in free state. Al³⁺ ions form complex ion groups with F^- and O^2- ions. The Al-F complex ion groups are composed of [AlF₆]^3-, [AlF₅]^2- and [AlF₄]^-. The Al-O-F complex ion group is formed by replacing F^- in the Al-F complex ion group with O^2-. The average distance between Al-F and Al-O ion pairs is 1.725 ?. In the system containing KF, the coordination number of Al-F ion pair is higher than that of other systems, while the coordination number of Al-O ion pair is lower than that of other systems. Na⁺, Ca²⁺, Li⁺ and K⁺ have strong diffusion ability, while Al³⁺ and O^2- have relatively weak diffusion ability, and F^- has slightly stronger diffusion ability than Al³⁺. In the system containing LiF and KF, the Al-F bond is more stable, while the Al-O bond is more stable in the system containing LiF.更多还原