Preparation and stability of a new compound SrCe0.9Lu0.1O2.95

The preparation of SrCeO3 doped by lutetium oxide (SrCe0.9Lu0.1O2.95) has been carried out by the solid-state reaction of SrCO3, CeO2 and Lu2O3. The X-ray measurements have shown that SrCe0.9Lu0.1O2.95 has an orthorhombic structure (space group Рnma). For the first time the standard molar enthalpy of SrCe0.9Lu0.1O2.95 formation has been determined by solution calorimetry in combination with standard molar dissolution enthalpies of SrCe0.9Lu0.1O2.95 and SrCl2 + 0.9CeCl3 + 0.1LuCl3 mixture in 1 M HCl with 0.1 M KI at 298.15 K and other thermochemical data. It has been found out that the mixed oxide mentioned above is thermodynamically more stable than the component oxides at room temperature. It has been also shown that SrCe0.9Lu0.1O2.95 is thermodynamically more favored than 0.9SrCeO3 + 0.1SrO + 0.05Lu2O3 mixture. We have established that Lu adding increases SrCeO3 thermodynamic stability.