Influence of Nb5+ Substitution on the Phase Formation, Microstructure and Electrical Properties of SBNLT Ceramics Synthesized via the Solid-State Combustion Technique

Abstract

In this study, the phase formation, microstructure, and electrical properties of Sr0.3(Bi0.70Na0.67Li0.03)0.5(Ti1-xNbx)O3: SBNLT-Nbx lead-free ceramics synthesized via the solid state combustion technique were examined. SBNLT-Nbx ceramics with various Nb content of x = 0, 0.01, 0.03, and 0.05 were calcined at 750 °C and sintered at 1175 °C for 2 h, respectively. The SBNLT-Nbx calcined powders showed a perovskite structure and a secondary NbO2 phase was observed with Nb5+ content of 0.03 and 0.05 mol%. All SBNLT-Nbx ceramics exhibited a pure perovskite phase with coexisting rhombohedral and tetragonal phases. The grain size was in the range of 1.17-1.34 µm. The ε max and tan δ max tended to decrease with increased x content. The best ferroelectric and energy storage properties (P max = 27.45 µC/cm2, P r = 1.92 µC/cm2 and W total = 0.958 J/cm3, W rec = 0.739 J/cm3, W loss = 0.219 J/cm3, η = 77.1%), measured under an electric field of 70 kV/cm, were observed at x = 0.01.