The structure of CeAlO3 by Rietveld refinement of X-ray powder diffraction data

The room temperature structure of perovskite CeAlO3 has been reinvestigated by X-ray powder diffraction. The Rietveld refinement has confirmed the tetragonal symmetry; but revealed a super cell, a = 5.32489(6) Angstrom and c = 7.58976(10) Angstrom, with the space group I4/mcm. In CeAlO3, the distortion from the ideal cubic perovskite is caused by the cooperative tilting of the AlO6 octahedra around the primitive cubic [001](p)-axis. (C) 2004 Elsevier Inc. All rights reserved.