Structural investigations on some complex titanates

Studies have been carried out on A2B2O7 type rare-earth titanates. Ferroelectric properties of Pr2Ti2O7 have been investigated from structural studies. Composition dependent structural studies have been carried out on zirconolite to understand the solubility limits and structural transitions. On substitution of rare-earth ions, the 2-layer zirconolite structure transforms to 4-layer zirconolite type structure. A number of rutile related complex solid solution compositions as MTiTaO6 exhibiting relaxor ferroelectric properties have prepared and characterized in details. The structural phase transition of morphotropic phase boundary composition in PbTiO3-Pb(Sc0.5Nb0.5O3) has been investigated by high temperature X-ray diffraction method and composition. Two coexisting monoclinic structure at ambient temperature has been observed from the structural studies. The transition from ferroelectric to paraelectric transition though an intermediate tetragonal structure is observed by in situ high temperature XRD and polarization studies. Salient details of these studies will be discussed in this presentation