Correlation between structure and Rayleigh parameters in the lead-free piezoceramic (1-x)Ba(Ti0.88 Sn0.12)O3-x(Ba0.7Ca0.3)TiO3

TL;DR

This study investigates how the crystal structure of lead-free piezoceramics correlates with their Rayleigh dielectric parameters, revealing phase-dependent behaviors and a link between Rayleigh parameters and coercive fields.

Contribution

It provides the first detailed correlation between structural phases and Rayleigh parameters in (1-x)Ba(Ti0.88 Sn0.12)O3-x(Ba0.7Ca0.3)TiO3 ceramics, highlighting phase boundary effects.

Findings

Irreversible dielectric response peaks near phase boundaries.

Orthorhombic compositions show enhanced irreversible contributions.

Rayleigh parameter correlates with coercive field.

Abstract

Composition dependent Rayleigh and structural analysis was carried out on the lead-free piezoceramics (1-x)(BaTi0.88Sn0.12)-x(Ba0.7Ca0.3)TiO3 at room temperature. The system exhibits tetragonal (P4mm) structure for x > 0.21, rhombohedral (R3m) for x < 0.13 and orthorhombic (Amm2) for 0.13<x<0.21. Rayleigh analysis suggests that the irreversible contribution to the dielectric response is enhanced in the single phase orthorhombic compositions in the vicinity of the R3m-Amm2 and Amm2-P4mm phase boundaries, and not in compositions exhibiting phase coexistences (x = 0.12 and 0.22). We also found a correspondence between the irreversible Rayleigh parameter and the coercive field in this system.