Synthesis, structural evolution, and dielectric properties of a new perovskite solid solution (Pb0.5Sr0.5)(Zr0.5Ti0.5)O3-PbTiO3

To explore lead-reduced dielectric materials in the SrTiO3-PbTiO3-PbZrO3 ternary system, a novel solid solution between relaxor ferroelectric (Pb0.5Sr0.5)(Zr0.5Ti0.5)O-3 and ferroelectric PbTiO3, namely (1 - x)(Pb0.5Sr0.5) (Zr0.5Ti0.5)O-3-xPbTiO(3) (lead-strontium-zirconate-titanate [PSZT]-PT), has been synthesized in the perovskite structure by high-temperature solid-state reaction method in the form of ceramics. The crystal structure and phase symmetry of the materials synthesized were analyzed and resolved based on X-ray powder diffraction (XRD) data through both the Pawley and Rietveld refinements. The results of the structural refinements indicate that at low PT-concentration end of the solid solution system, for example, x = 0.05, the PSZT-PT solid solution exhibits a cubic structural symmetry (with the space group Pm-3m). As the PT concentration (x) increases, the structure of (1 - x)PSZT-xPT gradually transforms from the cubic to a tetragonal (P4mm) phase. In the composition range of x = 0.10-0.25, a mixture of the cubic and tetragonal phases was identified. As the concentration of PT increases, the proportion of the tetragonal phase increases at the expense of the cubic phase. For a composition of x > 0.25, a pure tetragonal phase is observed. The dielectric properties of the materials were studied by measuring the permittivity as a function of temperature at various frequencies. For the composition of x = 0.05, the temperature dependence of dielectric constant shows typical relaxor behavior. For x = 0.35, the dielectric peaks indicate a normal ferroelectric phase transition. Overall, a structural transformation from a central-symmetric, nonpolar cubic phase to a non-centrosymmetric, polar tetragonal phase is induced by the substitution of PT for PSZT in the pseudo-binary solid solution of (1 - x)PSZT-xPT, which also reveals an interesting relaxor to ferroelectric crossover phenomenon.

Automated summary

In this study, a novel solid solution (1-x)(Pb0.5Sr0.5)(Zr0.5Ti0.5)O-3-xPbTiO(3) was synthesized to explore lead-reduced dielectric materials. The crystal structure and dielectric properties were studied, revealing a structural transformation from a cubic phase to a tetragonal phase. The temperature dependence of dielectric constant exhibits relaxor behavior or a normal ferroelectric phase transition.