Excellent thermal stability and low dielectric loss of (Ba1 − xBi0.5xSr0.5x)(Ti1 − xBi0.5xZr0.5x)O3 solid solution ceramics in a broad temperature range applied in X8R

Abstract

(Ba1 − xBi0.5xSr0.5x)(Ti1 − xBi0.5xZr0.5x)O3 [BBSTBZ, 0.02 ≤ x ≤ 0.1] ceramics were synthesized by a traditional solid-state reaction technique. The transition from tetragonal phase to pseudocubic phase at 0.06 ≤ x ≤ 0.08 was observed in Raman spectra and X-ray diffraction patterns. With adding (Bi3+, Sr2+, Zr4+), the thermal-stability of relative permittivity (Δe/e25 °C) and dielectric loss (tan δ) of ceramics were optimized. Especially, (Ba0.9Bi0.05Sr0.05)(Ti0.9Bi0.05Zr0.05)O3 ceramics with small Δe/e25 °C value (≤ ± 15%) in a wide temperature range of − 70 °C to 155 °C, high er (er ~ 2088–2116) and tan δ (tan δ ≤ 0.02) from − 10 °C to 200 °C were obtained, which indicates that BBSTBZ is suitable for X8R applications. Impedance spectroscopy was used to analyse the conduction and relaxation processes. The results showed that the relaxation and conduction process in the high-temperature region are thermally activated, and the oxygen vacancies are charge carriers.