Crystal structures and crystal chemistry of the RETiO3 perovskites: RE = La, Nd, Sm, Gd, Y

The structures of the RETiO3 perovskites, RE = La, Nd, Sm, Gd, and Y, were solved using single-crystal, automated diffractometer techniques. All were found to belong to space group Pbnm and are, therefore, isostructural with the REFeO3 perovskites. The structure of LaTiO3 was solved using a crystal exhibiting a complex twinning. The REO and TiO coordination polyhedra were studied as a function of the RE ion and were compared with those for REFeO3. The major difference in results between RETiO3 and REFeO3 is a more highly distorted TiO octahedron for RE = Gd and Y.