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Abstract: Thermodynamic parameters of the La2O3–Y2O3 and La2O3–Al2O3 binary systems were re-assessed based on new experimental information. Phase relations in the La2O3–Y2O3–Al2O3 system were investigated at temperatures 1523, 1673 and 1873K by phase equilibration followed by phase identification by X-ray diffraction and microstructure investigation by scanning electron microscopy. Melting relations in the system were studied by differential thermal analysis. Temperature and liquid composition for two invariant reactions were determined. The obtained results were used to developed thermodynamic database for the La2O3–Y2O3–Al2O3 system. Mutual solubility of La and Y in aluminates was taken into account. The obtained thermodynamic description was combined with already available databases of ternary systems and thermodynamic database of the ZrO2–La2O3–Y2O3–Al2O3 was derived. [Copyright &y& Elsevier]

Abstract: The Nd2O3–Al2O3 and ZrO2–Nd2O3–Al2O3 systems were simultaneously re-assessed to reproduce experimental data from present study and literature. Phase relations in the Nd2O3–Y2O3–Al2O3 system were investigated by XRD, electron microscopy and DTA for the first time. Invariant reaction in solid phases B+YAM=NdAlO3 +C was determined to occur at 1863K. The eutectic reaction liquid=YAG+NdAlO3 +Al2O3 was determined to occur at 2042K and composition Al2O3–10mol.% Nd2O3–13mol.% Y2O3. The obtained data were used to assess thermodynamic parameters of this system. Isothermal sections were calculated in the range 1523–1923K. Liquidus surface of the Nd2O3–Y2O3–Al2O3 system was calculated. The derived databases were combined with already available descriptions of the ZrO2–Nd2O3–Y2O3 and ZrO2–Y2O3–Al2O3 systems into four-oxide database. [Copyright &y& Elsevier]