Relaxor Behavior and Dielectric Relaxation in Lead-Free Solid Solutions of (1 − x)(Bi0.5Na0.5TiO3)–x(SrNb2O6)

Abstract

Lead-free compositions (1 − x) (Bi0.5Na0.5TiO3)–x(SrNb2O6) (BNT-SN) are synthesized by a simple solid state reaction route. SN diffuse in distorted perovskite BNT for low concentrations of SN (x ≤ 0.03) and are stabilized in rhombohedral perovskite phase with experimentally observed relative density of the ceramics >92%. A temperature-dependent dielectric response exhibits a broad dielectric peak that shows frequency-dependent shifts towards higher temperatures reflecting typical relaxor behavior. Modified Curie–Weiss law and Lorentz-type empirical relationships are used to fit the dielectric data that exhibit almost complete diffuse phase transition characteristics. In addition, significant dielectric dispersion is observed in a low-frequency regime in both components of the dielectric response and a small dielectric relaxation peak is observed. Cole–Cole plots indicate the poly-dispersive nature of the dielectric relaxation.