LAUSR

Materials based on CeO2-La2O3-Eu2O3 and La2O3-Eu2O3 systems are promising candidates for a wide range of applications, but the phase relationship has not been studied systematically previously. The phase relations in the CeO2-La2O3-Eu2O3 ternary system at 1500?C and binary La2O3-Eu2O3 system at 1600-1500?C were studied in air by X-ray diffraction (XRD) investigation in the overall concentration range. The isothermal section of the phase diagram for the CeO2-La2O3-Eu2O3 system has been constructed. It was established that in the ternary CeO2-La2O3-Eu2O3 system there exist fields of solid solutions based on hexagonal (A) modification of La2O3, cubic modification of CeO2 with fluorite-type structure (F), cubic (C) and monoclinic (B) modification Eu2O3. It was established that in the binary La2O3-Eu2O3 system there exist fields of solid solutions based on hexagonal (A) modification of La2O3 and monoclinic (B) modification Eu2O3. The phases were separated by two-phase fields (A+B). The refined lattice parameters of the unit cells for solid solutions and microstructures of the definite field of compositions for the systems were determined.