PrCl_3-BaCl_2-LiCl三元体系相图的研究

AN INVESTIGATION ON PHASE DIAGRAM OF TERNARY SYSTEM PrCl_3-BaCl_2-LiCl

本文借助于DTA与X射线结构分析研究了PrCl_3-BaCl_2-LiCl三元体系相同。发现本体系内有对应于PrCl_2、α-BaCl_2、β-BaCl_2、LiCl和Ba_2PrCl_3的五个液相面、六条二次结晶线、一个三元低共熔点E(72.1wt%PrCl_3,2.8wt%BaCl_2,25.1wt%LiCl;441℃)和三元转熔点P(62.5wt%PrCl_3,12.5wt%BaCl_2,25.0wt%LiCi;490℃)。同时发现有一固相下形成的不稳定化合物Y(430℃分解)。

The phase diagram of ternary system PrCl_3-BaCl_2-LiCl has been investigated by means of DTA and X-ray diffraction analysis. It is found that there are 5 surfaces corresponding to the primary crystallization of PrCl_3, α-BaCl_2, β-BaCl_2,LiCl and Ba_3PrCl_9 respectively and 6 univariant lines related to the secondary crystallization in this system.The two reactions occurred in this system are:L(?)LiCl+PrCl_3+Ba_3PrCl_9E(72.1wt%PrCl_3, 2.8wt%BaCl_2, 25.1wt%LiCl; Temp.441℃)L+△β-BaCl_2(?)Ba_3PrCl_9+LiClP(62.5wt%PrCl_3, 12.5wt%BaCl_2, 25.0wt%LiCl; Temp.490℃)A compound, formed in the solid state, was found.The temperature of decomposition occures at 430℃.