Structural, dielectric, ferroelectric and tuning properties of Pb-free ferroelectric Ba0.9Sr0.1Ti1-xSnxO3

TL;DR

This study systematically investigates Pb-free Ba0.9Sr0.1Ti1-xSnxO3 ceramics, revealing phase evolution, enhanced dielectric permittivity, and high tunability at room temperature, demonstrating their potential for tunable electronic applications.

Contribution

It provides a comprehensive analysis of how Sn substitution affects phase structure, dielectric, and ferroelectric properties of Ba0.9Sr0.1TiO3 ceramics, highlighting optimal compositions for tunable devices.

Findings

Maximum dielectric permittivity of ~35000 at x=0.10

High tunability of 63% at room temperature

Phase evolution from tetragonal to cubic with increasing Sn content

Abstract

A series of Pb-free ferroelectric materials Ba0.9Sr0.1Ti1-xSnxO3 (BSTS-x) with 0 < x < 0.15 was successfully prepared via solid-state reaction method. The effect of Sn substitution on the crystal structure, microstructure, dielectric behavior, ferroelectric and tunable features of BSTS-x ceramics were systematically investigated. Room temperature (RT) x-ray diffraction (XRD) analysis using the Rietveld refinement method reveals that all the synthesized BSTS-x ceramics were well crystallized into single perovskite structure. The results show a tetragonal phase for 0.00 < x < 0.02, which evolves to orthorhombic and tetragonal coexisting phases for 0.05 < x < 0.07. The composition x = 0.10 showed a mixture of tetragonal, orthorhombic and rhombohedral phases at RT, while a single cubic phase is observed for x = 0.15. The crystal phases determined by XRD were confirmed by Raman spectroscopy. Enhanced dielectric permittivity with a maximum value of {\epsilon}'~ 35000 is observed for x = 0.10 at RT. The ferroelectric behavior of BSTS-x ceramics was investigated through polarization hysteresis loops and tunability measurements. High tunability of 63% at RT and under the low DC-applied electric field of 1.40 kV/cm is achieved for x = 0.10.