Low temperature structural studies on PrAlO₃

Abstract

The structures of PrAlO3 have been studied from room temperature to 10 K, using a combination of high resolution neutron and synchrotron powder diffraction data. At room temperature, PrAlO3 has a rhombohedral structure in space group Rc which transforms to an orthorhombic structure in Imma on lowering the temperature to about 205 K, and to a monoclinic, C2/m, structure at about 150 K. The structure becomes more nearly tetragonal as the sample is further cooled, but the high resolution diffraction confirms that the symmetry remains monoclinic in space group C2/m down to the lowest measured temperature.