(Ba1-xBix)(Ti1-xNi0.5xSn0.5x)O3 Solid Solution: Phase Evolution, Microstructure, Dielectric Properties, and Impedance Analysis

(Ba1-xBix)(Ti1-xNi0.5xSn0.5x)O-3 (BBTNS, 0.02 <= x <= 0.1) samples have been synthesized by traditional solid-state reaction technique and their structural transformation and dielectric properties investigated. X-ray diffraction (XRD) analysis revealed that BBTNS could form a homogeneous solid solution, and the transformation from tetragonal to pseudocubic phase occurred at 0.04 <= x <= 0.06. Optimized properties with stable epsilon(r) (similar to 1829 to 1838), small Delta epsilon/epsilon(25 degrees C) values (+/- 15%) over a broad temperature range from -60 degrees C to 140 degrees C, and low tan delta (<= 0.02) from 4 degrees C to 194 degrees C were obtained at x = 0.1. The relaxation and conduction process in the high-temperature region are attributed to thermal activation, and oxygen vacancies may be the ionic charge carriers in perovskite ferroelectrics.