Materials produced from cerium oxides stabilized by rare-earth metal (REM) oxides are promising for medical and engineering applications for their unique properties. The CeO₂–La₂O₃–Ln₂O₃ phase diagrams serve as a physicochemical basis for developing solid electrolytes for fuel cells, oxygen sensors, catalyst carriers, protective coatings on alloys, etc. Phase equilibria and structural transformations in the CeO₂–La₂O₃–Sm₂O₃ system at 1250°C were studied by X-ray diffraction over the entire composition range. The studies revealed fields of solid solutions based on the cubic (F) fluorite-type modification of CeO₂, monoclinic (B) and cubic (C) modifications of Sm₂O₃, and hexagonal (A) modification of La₂O₃ in the ternary CeO₂–La₂O₃–Sm₂O₃ system at 1250°C had predominantly cubic phases in equilibrium: CeO₂-based F-phase with Fm3m space group and Sm₂O₃-based C-phase with Ia3 space group. The lattice parameters of the fluorite-type (F-CeO₂) cubic solid solutions changed from a = 0.5409 nm for pure CeO₂ to a = 0.5515 nm for the two-phase (F + C) 55 CeO₂–22.5 La₂O₃–22.5 Sm₂O₃ sample (mol.%) along section La₂O₃ : Sm₂O₃ = = 1 : 1, to a = 0.5548 nm for the two-phase 55 CeO₂–33.75 La₂O₃–11.25 Sm₂O₃ sample along section La₂O₃: Sm₂O₃ = 3 : 1, and to a = 0.5478 nm for the two-phase (F + C) 60 CeO₂–10 La₂O₃–30 Sm₂O₃ sample along section La₂O₃ : Sm₂O₃ = 1 : 3. At 1250°C, the cubic F-CeO₂ fluorite-type solid solutions are in equilibrium with all phases formed in the system. The isothermal section of the CeO₂–La₂O₃–Sm₂O₃ phase diagram at 1250°C contains two three-phase (A + F + B, F +B + C) and five two-phase (A + F, A + B, F + B, B + C, F + C) regions.

由稀土金属 (REM) 氧化物稳定的氧化铈生产的材料因其独特的性能而有望用于医疗和工程应用。CeO ₂ –La ₂ O ₃ –Ln ₂ O ₃相图是开发用于燃料电池、氧传感器、催化剂载体、合金保护涂层等的固体电解质的物理化学基础。 CeO ₂中的相平衡和结构转变–La ₂ O ₃ –Sm ₂ O ₃通过 X 射线衍射在整个组成范围内研究了 1250°C 下的系统。所述研究揭示基于三次（F）的固溶体的CeO萤石型修饰的字段₂，单斜（B）和立方（C）的Sm的修改₂ ö ₃，和La的六边形（A）变形例₂ ö ₃在在 1250°C 时，三元 CeO ₂ –La ₂ O ₃ –Sm ₂ O ₃系统在平衡状态下主要为立方相：CeO ₂基 F 相，具有 Fm3m 空间群和 Sm ₂ O ₃基于 Ia3 空间群的 C 相。萤石型 (F-CeO ₂ ) 立方固溶体的晶格参数从纯 CeO ₂的 a = 0.5409 nm 变为两相 (F + C) 55 CeO ₂ –22.5 La ₂ O 的a = 0.5515 nm ₃ –22.5 Sm ₂ O ₃样品 (mol.%) 沿 La ₂ O ₃ : Sm ₂ O ₃ = = 1 : 1，至 a = 0.5548 nm 两相 55 CeO ₂ –33.75 La ₂ O ₃ –沿 La ₂ O ₃截面的11.25 Sm ₂ O ₃样品：Sm₂ O ₃ = 3 : 1，对于两相 (F + C) 60 CeO ₂ –10 La ₂ O ₃ –30 Sm ₂ O ₃样品沿 La ₂ O ₃ : Sm ₂ O 的a = 0.5478 nm ₃ = 1 : 3。在1250°C时，立方F-CeO ₂萤石型固溶体与系统中形成的所有相都处于平衡状态。CeO ₂ –La ₂ O ₃ –Sm ₂ O ₃的等温截面 1250°C时的相图包含两个三相（A+F+B、F+B+C）和五个两相（A+F、A+B、F+B、B+C、F+C）地区。