The ferroelectric phase of CdTiO3: a powder neutron diffraction study

Abstract

The synthesis of bulk samples of polycrystalline CdTiO(3) in both the rhombohedral ilmenite and orthorhombic perovskite forms is described and the structures of these have been refined using powder neutron diffraction data. This involved the preparation of samples enriched in (114)Cd. Cooling perovskite-type CdTiO(3) to 4 K induces a ferroelectric phase transition, with the neutron data suggesting the low temperature structure is in Pna2(1). Mode analysis shows the polar mode to be dominant at low temperatures. The ilmenite-structure of CdTiO(3) is compared with that of ZnTiO(3). The refined scattering length of the (114)Cd is estimated to be 5.56 fm. Attempts to dope CdTiO(3) with Ca and Sr are described. (C) 2011 Elsevier Inc.