铝的低温电解质体系基础研究之一：MCl—M3AlF6（M=Na,K）二元…

将双亚晶格模型应用于含络离子的铝电解质体系中，基于ＣＡＬＰＨＡＤ技术利用ＰＡＲＲＯＴ优化程序块对ＭＣｌ－Ｍ３ＡｌＦ６（Ｍ＝Ｎａ，Ｋ）伪二元系相图进行优化计算，得到了热力学数据自洽一致的结果，并对结果进行了分析讨论。     

基于FORTRAN的Ca-Fe-Si-O体系logf（O2）-loga（SiO2）相图的计算

以Ca-Fe-Si-O体系多相组合的logf（O₂）-loga（SiO₂）相图为例介绍了一种相图计算方法及Fortran95语言编程的实现过程。首先根据Gibbs相律确定了各个单变度和无变度组合,并根据化学成分图解配平化学反应方程式。然后,按照文献中的模型和参数计算各种矿物相和组分的Gibbs自由能,进而在给定的温度压力下计算各条反应平衡线的logf（O₂）和loga（SiO₂）值。然后再根据Schreinemakers规则判断相图中介稳的相关系,并从计算结果中去掉单变度反应线的介稳部分和介稳的无变度点。最后讨论了温度、压力对平衡的影响和新的矿物相加入时的计算方法和注意事项。     

Thermodynamic optimization and calculation of the ErCl3–MCl (M=Li,Na,K,Rb,Cs ) systems

In this paper, the binary phase diagrams of the ErCl₃–MCl (M = Li, Na, K, Rb, Cs) systems were studied by the CALPHAD (CALculation of PHAse Diagram) approach. The modified quasi-chemical model in the pair-approximation for short-range ordering was used to describe the Gibbs energies of the liquid phase in the systems. From measured phase diagram data and experimental thermochemical properties, a series of thermodynamic functions has been optimized based on computer-assisted analysis. A discussion of thermodynamic functions for strong interaction binary systems was undertaken. The results showed that the calculated phase diagrams and optimized thermodynamic parameters are self-consistent.     

Phase equilibria in LaBr3-TlBr pseudobinary system. Thermodynamic assessment of LaBr3-MBr (M = Li,Na, K,Rb, Cs,Tl) pseudobinary systems

The phase equilibria in the lanthanum(III) bromide-thallium bromide pseudobinary system was established by means of differential scanning calorimetry (DSC). The DSC investigations were performed on samples with different compositions in the whole mole fraction x(LaBr₃) range. This system includes one intermediate compound Tl₂LaBr₅. It melts congruently at 829 K. The compositions of TlBr-Tl₂LaBr₅ and Tl₂LaBr₅-LaBr₃ eutectics, corresponding to LaBr₃ mole fraction x = 0.088 (T = 687 K) and x = 0.491 (T = 788 K) respectively, was found from Tammann's plot. The LaBr₃-TlBr pseudobinary system was also optimized by CALPHAD method using the available experimental data. Experimental and calculated data concerning LaBr₃-TlBr system were compared with data for LaBr₃-MBr (M = Li-Cs) systems, which have also been optimized by CALPHAD method. The thermodynamic properties of the liquid phase in the systems were modelled using the Associated Solution Model with {3 M⁺ + LaBr₆³⁻} (M = Li-Cs, Tl) associate. The dependencies of mixing enthalpy and mixing entropy on mole fraction x(LaBr₃) were estimated for all investigated systems. The dependencies of formation Gibbs energy on temperature and temperature range of existence of intermediate compounds have been calculated and discussed. The CALPHAD optimization indicates that the participation of the associate in the liquid phase in the LaBr₃-MBr (M = K⋯Cs, Tl) systems increases with the increase of the ionic radius of the monovalent metal.