Concentration and temperature-driven phase transitions in the NdAlO3-EuAlO3 system

Phase and structural behaviour in the NdAlO3-EuAlO3 system has been studied in a whole concentration range. Depending on x two kinds of solid solutions Nd1−xEuxAlO3 one with rhombohedral (x ≤ 0.15) and one with orthorhombic (x ≥ 0.25) symmetry exist at room temperature. A morphotropic phase transition occurs at x ≈ 0.20, where the co-existence of both phases was observed. First-order structural phase transition Pbnm↔R 3 c has been detected in Nd0.6Eu0.4AlO3 at 627 K both from in situ high-temperature X-ray synchrotron powder diffraction and thermal analysis data.