THE NATURE OF MOLTEN-SALT-LIQUID-METAL SOLUTIONS

The microscopic structure of certain molten-salt-liquid-metal solutions has been investigated by quantum chemical method. It is indicated that (ⅰ) Li_(n 1)~(n ) or Li_(n 2)~(n ) ions form in Li-LiF melt. The valence electrons of Li atoms delocalize into all vacant orbitals of neighboring cations; (ⅱ) lithium fluoride, dissolving in liquid lithium, forms F~- ions in liquid metal, and the vacant orbitals of Li~ ions of the salt take part in the delocalization with the electrons of metallic bond. It is this delocalizatin energy that makes this solution thermodynamically stable; (ⅲ) Mg_2~(2 ) is unstable as compared with Mg~ or Mg_2~ . The experimental results of mass-spectroscopy also indicate the existence of Mg~ abd Mg_2~ , but not Mg_2~(2 ). The state of Mg dissolving in molten salt is discussed based on the results mentioned above.     

Al_x Ga_(1-x) As二次离子质谱定量分析

本文提出了一种用二次离子质谱(SIMS)测定Al_x Ga_(1-x)As薄膜样品成分的定量分析方法,通过对一组标样用线性回归法定标和迭代法定量计算,对不同能量下得到的数据进行统计分析表明,用SIMS方法测定的组份X值与用电子探针测定的结果之间的均方根误差只有8.7。本文还对影响SIMS定量分析精度的某些实验因素作了探讨。并给出了估算Al组分的I(Al~+)/sum from j=1 to nI(M_j~+)～C_(Al)图。原则上本法也同样适用于其它多组分均匀样品的SIMS定量分析。     

若干熔盐-液体金属溶液的量子化学研究

本文用量子化学方法研究了若干熔盐-液体金属溶液的微观结构.证明Li溶入LiF熔盐中形成Li_(n 1)~(n )或Li_(n 2)~(n )一类原子簇离子.LiF溶入液体Li后Li~ 离子空轨道参与金属键电子离域,离域能是Li和LiF熔体互相溶解的推动力.量子化学计算表明Mg_2~(2 )不如 Mg~ 和Mg_2~ 稳定.质谱实验亦证明 Mg~ 和Mg_2~ 的存在而不能发现Mg_2~(2 ).据此讨论了Mg在含Mg~(2 )熔盐中溶解的机理。