The ferroelectric phase of CdTiO3: A powder neutron diffraction study

The synthesis of bulk samples of polycrystalline CdTiO3 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 114Cd. Cooling perovskite-type CdTiO3 to 4 K induces a ferroelectric phase transition, with the neutron data suggesting the low temperature structure is in Pna21. Mode analysis shows the polar mode to be dominant at low temperatures. The ilmenite-structure of CdTiO3 is compared with that of ZnTiO3. The refined scattering length of the 114Cd is estimated to be 5.56 fm. Attempts to dope CdTiO3 with Ca and Sr are described.

The structure of three phases of CdTiO3 have been refined using high resolution powder neutron diffraction data. This involved the preparation of samples enriched in 114Cd. Cooling perovskite-type CdTiO3 to 4 K results in a ferroelectric phase in Pna21.Figure optionsDownload as PowerPoint slideHighlights
► Both the ilmenite and perovskite forms of CdTiO3 have been prepared using 114Cd.
► Cooling the perovskite form results in a ferroelectric phase.
► The structures of these are refined from powder neutron diffraction data.
► Attempts to dope CdTiO3 are described.