DyF_3－BaF_2－LiF三元系熔体结构的计算机模拟研究  

COMPUTERIZED SIMULATION OF STRUCTURE OF DyF_3-BaF_2-LiF MOLTEN SYSTEM

作　　者：徐驰[1] 苏航[1] 陈念贻[1] 李洁[1] 唐定骧[1] 

机构地区：[1]中国科学院上海冶金研究所,中国科学院长春应用化学研究所

出　　处：《金属学报》1995年第3期B097-B102,共6页Acta Metallurgica Sinica

基　　金：中国科学院长春应用化学研究所稀土化学与物理开放实验室科学基金

摘　　要：ＭｏｎｔｅＣａｒｌｏ法计算机模拟研究ＤｙＦ_３－ＢａＦ_２－ＬｉＦ三元系熔体，得到了离子间偏径向分布函数、局部结构和能量分布等信息．研究表明：Ｆ~－聚集在Ｄｙ^（３＋）周围，主要组成以ＤｙＦ_６^（３－）形式的八面体络离子；Ｌｉ~＋以“游离”状态存在，其平均位能较高，在电解中起到迁移电流的作用：氟离子可分为“端氟”、“游氟”和“桥氟”三类，不同行为的氟其位能也不同、通过“桥氟”组成诸如Ｆｍ－Ｄｙ－Ｆ－Ｄｙ－Ｆｎ或Ｆｍ－Ｄｙ　Ｄｙ－Ｆｎ较复杂的离子集团；与ＤｙＦ_３－ＬｉＦ二元系熔体模拟结果相比较，ＢａＦ_２的加入使ＤｙＦ_６^（３－）形式的八面体络离子较为紧密及有序．The structure of molten DyF_3-BaF_2-LiF system has been simulated by Monte Carlo method. The radial distribution functions (RDFs), the local structure as well as the energy distribution have been obtained. The study indicates that F-ions distribute closely around Dy￣(3+) ions and form mainly octahedral complex ions like DyF_6￣(3-). There exist some 'free' Li￣+ ions in the molten system, they have the highest potential energy and are currentcarrying ions in the electrolytic conductance. F￣-ions may be classified into three types: 'terminal fluoride', 'free fluoride', and 'bridged fluoride', which have different behaviours. and their potential energies are also different. Some complex ions like DyF_m￣(3-m) clusters are connected to one another by 'flouride-bridge', forming more complicated ionic cluster like F_m-Dy-F-Dy-F_n or F_m-Dy< >Dy-F_n. As compared with molten DyF_3-LiF system.the octahedral complex ions like DyF_6￣(3-) seems more close and more order than the binary system because of adding of BaF_2.

关 键 词：稀土氟化合物 熔盐 计算机模拟 熔体结构 稀土族 

分 类 号：O614.33[理学—无机化学]