Structural and ferroelectric properties of perovskite Pb(1-x)(K0.5Sm0.5)xTiO3 ceramics

TL;DR

This study investigates how substituting Pb with K and Sm in PbTiO3 affects its structural and ferroelectric properties, revealing phase transitions and retained ferroelectricity at high substitution levels.

Contribution

It introduces a new substitution model using K and Sm to replace Pb in PbTiO3, analyzing resulting changes in structure and electrical behavior.

Findings

Phase transition from tetragonal to cubic occurs at lower temperatures with substitution.

Ferroelectricity persists even at high substitution levels (x=0.5).

Structural and dielectric properties are significantly modified by substitution.

Abstract

PbTiO3 has the highest tetragonal distortion (c/a=1.064) and highest spontaneous polarization among perovskite titanates. But, it is hazardous and hence one needs to reduce Pb content by substituting or reducing Pb content for use in applications. Pb(1-x)(K0.5Sm0.5)xTiO3 (0&x&0.5) perovskite powders were synthesized by sol-gel process, where Pb2+ was replaced by a combination of K+10.5Sm+30.5 (equivalent charge and comparable ionic radius) providing an excellent substitution model to study changes in structural and electrical properties. Vibrational properties and dielectric properties are modified with substitution. A polar tetragonal to a nearly nonpolar cubic phase transition decreases to lower temperatures with substitution due to reduces the lattice strain with substitution. Ferroelectricity is retained even for x=0.5, which has a nearly cubic phase and makes the material technologically important.