在LiF-BeF2-ThF4溶盐中的局部结构和离子扩散:从Ab Initio分子动力学的洞察
Yuan Yin1, Wenshuo Liang2, Dezhong Wang1
1School of Nuclear Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
The journal of physical chemistry. B
|April 22, 2025
概括
计算模拟揭示了四化物 (ThF4) 如何影响先进核反应堆中化物盐的结构和离子运动. 较高的ThF4度降低了FLiBeTh盐中的整体离子扩散.
科学领域:
- 材料科学 材料科学 材料科学
- 核工程 核工程是指核工程.
- 计算化学的计算化学
背景情况:
- 了解LiF-BeF2-ThF4 (FLiBeTh) 盐对于第四代核反应堆至关重要.
- 对这些放射性和有毒盐的实验研究具有挑战性.
- 计算模拟为材料分析提供了安全有效的替代方案.
研究的目的:
- 研究ThF4度对FLiBeTh融盐局部结构和离子扩散的影响.
- 为先进的核反应堆燃料应用提供FLiBeTh的行为见解.
主要方法:
- 在2LiF-BeF2系统上进行了初始分子动力学 (AIMD) 模拟,其THF4度 (0-18.18mol%) 在973 K.进行了变化.
- 分析包括辐射分布函数 (RDF),角分布函数 (ADF),协调数 (CN),平均平方位移 (MSD) 和离子居住比 (r) (t).
主要成果:
- 增加ThF4度对阳离子第一协调的影响很小,但表明了短距离的顺序.
- 协调数显示了Li+ (四/五),Be2+ (四) 和Th4+ (八) 协调.
- 离子扩散率遵循Li+ > F- > Be2+ > Th4+;Be-F和Th-F协调是稳定的,Li-F是动态的. 更高的ThF4降低了整体的MSD.
结论:
- AIMD模拟准确地描述了FLiBeTh融盐中的局部结构和离子扩散.
- 该研究证实,增加ThF4度降低了离子扩散,影响了盐的性能.
- 这些发现支持FLiBeTh作为第四代核反应堆的燃料盐的发展.
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