Study of A and B sites order in lanthanide-doped lead titanate ferroelectric system

Pb(0.88)Ln(0.08)TiO(3) ferroelectric system, where Ln = La, Sm, Eu, and Dy, has been characterized using Scanning Electron Microscopy, Raman spectroscopy, and X-ray diffraction experiments. Softening of the lowest transverse optical phonon mode E (1TO) was evaluated as a function of the rare earths' ionic radius suggesting partial occupation of lanthanide ions at the A and B sites of the perovskite structure. Using Rietveld refinements, it has been established a higher incorporation of Ln(3+) ions into the A sites of the perovskite structure than that of the B sites for the studied ceramics. The occupation at B sites increases slightly with the decreases of the ionic radii of the lanthanides. (C) 2016 International Centre for Diffraction Data.