Experimental phase diagram determination and thermodynamic assessment of the La2O3–SrO system Original Research Article

In the oxide portion of the La–Sr–O system there exist two intermediate phases, β with a certain homogeneity range centred around the stoichiometry La4SrO7 and a stoichiometric phase, La4Sr3O9. La2O3 dissolves a considerable amount of SrO, SrO only negligible amounts of La2O3. Microprobe analysis, X-ray diffraction and differential thermal analysis were used to determine the stability limits of the phases. Using the experimental data and assessed literature data, a thermodynamic description of the oxide portion of the system was optimised and the quasi-binary La2O3–SrO phase diagram calculated.