Compositional range and electrical properties of lead-free Bi<inf>0.5</inf>(Na<inf>0.8</inf>K<inf>0.2</inf>)<inf>0.5</inf>TiO<inf>3</inf>-(Ba<inf>0.98</inf>Nd<inf>0.02</inf>) TiO<inf>3</inf>system

Abstract

Lead-free piezoelectric ceramics (1-x)Bi0.5(Na0.8K0.2)0.5TiO3-x(Ba0.98Nd0.02)TiO3or (1-x)BNKT-xBNdT (x = 0.05-0.15 mol fraction) were synthesized by conventional mixed-oxide method. All samples had relative densities more than 98% of theoretical values. All compositions had pure perovskite structure and BNdT effectively diffused into BNKT lattice during sintering to form solid solutions. Grain size and shape were slightly affected by BNdT addition. The addition of BNdT into BNKT was also found to affect dielectric, ferroelectric and piezoelectric performances with the maximum values (Tm= 328°C, εr= 1736, tanδ = 0.0714, Pr= 21.91 μC/cm2, d33= 228 pC/N) observed in 0.89BNKT-0.11BNdT composition. © 2014 Copyright Taylor and Francis Group, LLC.