Structure and lattice dynamics in PbTiO3–Bi(Zn1/2Ti1/2)O3 solid solutions

(1−x)PbTiO3–xBi(Zn1/2Ti1/2)O3 solid solutions show a much enhanced tetragonality (c/a) and Curie temperature (TC). The detailed structure of (1−x)PbTiO3–xBi(Zn1/2Ti1/2)O3 is studied by means of neutron powder diffraction based on the Rietveld refinement. Zn exhibits a more polarizable property than Ti, resulting in a B-site cation splitting (0.27 A) between Zn and Ti along c-axis direction. The spontaneous polarization displacements are enhanced by the substitution of Bi(Zn1/2Ti1/2)O3. The lattice dynamics study of (1−x)PbTiO3–xBi(Zn1/2Ti1/2)O3 by Raman scattering spectroscopy reveals that the optical modes [A1 (1TO), A1 (2TO), and E (2TO)] are abnormally hardened by the substitution of Bi(Zn1/2Ti1/2)O3 for PbTiO3, indicating the enhanced PS and the strong hybridization between Pb/Bi and O. The ceramic of (1−x)PbTiO3–xBi(Zn1/2Ti1/2)O3 (x=0.3) exhibits a low dielectric loss (tan δ) due to the d0 electronic structure.