HoCl_3-MCl_n体系相图的研究(M=Li,Mg,Ca,Pb;n=1,2)

Phase Diagrams of Binary System HoCl_3-MCl_n (M = Li, Mg, Ca, Pb; n = 1,2)

借助于DTA与X射线衍射法研究了HoC_3-MCl_n(M=Li,Mg,Ca,Pb;n=1或2)二元体系相图.发现HoCl_3-LiCl体系相图属固液异组成型,有一化合物Li_3HoCl_6生成,且在483℃有一相转变.其无变点分别为p(34.0mol%HoCl_3,506℃)和e(50.5mol％HoCl_3,452℃); 而HoCl_3-MgCl_2,CaCl_2,PbCl_2。体系皆属简单低共熔型相图.其低共熔点e的组成与温度分别为:50.0mol％HoCl_3(580℃)、49.0mol％HoCl_3(541℃)和37.0mol％HoCl_3(422℃).HoCl_3-PbCl_2体系在固相下有一不稳定化合物PbHoCl_5生成,在408℃分解.同时探讨了RECl_3-LiCl相图的某些规律。

The phase diagrams of binary system HoCl3-MCln (M = Li, Mg, Ca, Pb; n = 1, 2) were investigated by means of DTA and X-ray diffraction analysis. It was found that HoCl3-LiCl system is of peritectic type with compound Li3HoCl6 and invariant points e (50.5mol%HoCl3, 452℃) as well as p (34.0mol%HoCl3, 506℃). HoCl3-MgCl2, CaCl2, and PbCl2 systems are of simple eutectic type with eutectic points 50.0mol%HoCl3(580℃), 49.0mol%HoCl3(541℃) and 37.0mol%HoCl3(422℃) respectively. Unstable compound, formed in the solid state, is PbHoCl5 and decomposes at 408 ℃. Some rules of phase diagram were explored.