CsI-EuI2二元系相图研究

利用差热分析及X射线粉末聚焦照相法研究了CsI-EuI2体系的相图(723K以上部分)。该体系的相图属于有三个三元化合物生成的低共熔型相图。其中CsEuI3和Cs3EuI5为固液同组成化合物, 它们的熔点分别为915K和814K。CsEu2I5为固液异组成化合物, 分解温度为744K。生成两个低共熔物, 其组成分别为14.3%和72.5%(以CsI摩尔百分数计), 低共熔点分别为738K和804K。对新化合物---Cs3EuI5进行了磁性、XPS、荧光光谱、密度等方面的研究, 晶体结构测定表明Cs3EuI5属六方晶系,a=1.4634(4)nm, c=1.8376(0)nm, r=120°, Z=8, Dc=4.619g.cm^-^3,Dm^2^9^8=4.549g.cm^-^3。

The study of CsI-EuI2 binary system

The CsI-EuI2 system has been studied by differential thermal analysis and X-ray powder diffraction Guinier techniques. The phase diagram belong to eutectic type with three componunds. The CsEuI3 and Cs3EuI5 are congruent compounds, their melting points are 915K and 814K respectifly, the CsEu2T5 is one incongruent compound, peritectic point is 744K. There are two eutectic species, their eutectic points occur at 738K and 804K with 14.3 mol% CsI and 72.5mol% CsI. The crystal structural investigation of Cs3EuI5 show that it is hexagonal system: a=1.4634(4)nm, c=1.8376(0)nm, Dc=4.619g.cm^-^3, Dm^2^9^8=4.549g.cm^-^3. The valence of europinum in Cs3EuI5 has been determined by magnetic susceplibility, XPS and fluorescence spectry.