Phase and Structural Behaviour of the PrAlO3-SmAlO3System

High resolution in situ X-ray powder diffraction applying synchrotron radiation and differential thermal analysis/scanning calorimetry methods have been used to examine the pseudo-binary system PrAlO 3 -SmAlO 3 .Two kinds of solid solutions with rhombohedral and orthorhombic structure exist at room temperature.At elevated temperatures, a continuous phase transition P m3m ↔ R3c and a first-order transformation R3c ↔ P bmn occur in the two respective phases.A sequence of low-temperature phase transformations R3c ↔ Imma ↔ C2/m has been detected in Pr 1-x Sm x AlO 3 samples with x < 0.35.Based on in situ powder diffraction and differential thermal analysis/scanning calorimetry data, the phase diagram of the pseudo-binary system PrAlO 3 -SmAlO 3 has been constructed.