Using the methods of X-ray phase and microstructural analyzes, phase equilibria and structural transformations in the ZrO₂ – La₂O₃ – Eu₂O₃ system at temperatures of 1500 and 1250 ºC in the whole range of concentrations were studied. Based on the obtained data, the corresponding isothermal cross sections are constructed. It is established that the fields of solid solutions are formed in the system on the basis of cubic (F) modification with fluorite type structure, tetragonal (T) modification ZrO₂, monoclinic (B) and cubic (C) modifications Eu₂O₃, hexagonal (A) modification La₂O₃, as well as ordered phases with a structure of the pyrochlor type Ln₂Zr₂O₇ (Py). The boundaries of the phase fields and the parameters of the unit cells of the formed phases are determined. It was found that in the region with a high content of ZrO₂ solid solutions are formed on the basis of tetragonal modification of ZrO₂. The solubility of La₂O₃ in T-ZrO₂is small and is ∼ 0.5% (mol.), which is confirmed by X-ray phase analysis and microstructural studies. It is established that at 1500 and 1250°C a continuous series of solid solutions is formed on the basis of an ordered phase of pyrochlor (Py) type Ln₂Zr₂O₇. With decreasing temperature, the region of homogeneity of the specified solid solution narrows. Isothermal cross sections of the state diagram of the ZrO₂-La₂O₃-Eu₂O₃ system at 1500 and 1250°C have a similar structure, although they are characterized by some differences due to the structure of the limiting binary systems. No new phases in the ternary system ZrO₂ – La₂O₃ – Eu₂O₃ were detected at the studied temperatures.

使用X射线相和微观结构分析的方法，研究了ZrO ₂ -La ₂ O ₃ -Eu ₂ O ₃体系在1500和1250ºC的温度下在整个浓度范围内的相平衡和结构转变。基于获得的数据，构造相应的等温截面。建立了基于萤石型结构的立方（F）改性，四方（T）改性ZrO ₂，单斜晶（B）和立方（C）改性Eu ₂ O ₃的体系形成固溶体的场。，六角形（A）修饰La ₂ O ₃以及具有烧绿石型Ln ₂ Zr ₂ O ₇（Py）结构的有序相。确定相场的边界和所形成相的单位晶胞的参数。结果发现，在该区域用的ZrO含量高₂的ZrO四方修改的基础上形成的固溶体₂。La ₂ O ₃在T-ZrO _2中的溶解度很小，约为0.5％（摩尔），这已通过X射线相分析和微观结构研究得到证实。可以确定，在1500和1250°C的条件下，根据烧绿石（Py）型Ln ₂有序相形成了一系列连续的固溶体。Zr ₂ O ₇。随着温度降低，指定固溶体的均质区域变窄。ZrO ₂ -La ₂ O ₃ -Eu ₂ O ₃系统的状态图在1500和1250°C的等温截面具有相似的结构，尽管由于有限的二元体系的结构而具有一些差异。在研究温度下，未检测到三元体系ZrO ₂ -La ₂ O ₃ -Eu ₂ O _3的新相。