Structure and electrical properties of Ca2+-doped (Na0.47Bi0.47Ba0.06)TiO3 lead-free piezoelectric ceramics

Abstract The lead-free piezoelectric ceramics (Na .47 Bi .47 Ba .06 ) 1-x Ca x TiO 3 (x = 0, 0.01, 0.02, 0.03, 0.05, and 0.08, abbreviated as BNBTC/0, BNBTC/1, BNBTC/2, BNBTC/3, BNBTC/5, and BNBTC/8, respectively) were obtained using the solid-state reaction method. The structure, electric conductivity, and dielectric, ferroelectric, and piezoelectric properties of the Ca 2+ -doped (Na .47 Bi .47 Ba .06 )TiO 3 ceramics were thoroughly investigated. The ceramics sintered at 1200 °C exhibit dense microstructures, having relative densities higher than 96%. The X-ray diffraction results demonstrate that all ceramics have a pure perovskite structure. The mean grain sizes of the ceramics are related to the Ca 2+ quantity. A small quantity of Ca 2+ ions (x ≤ 0.03) improves the piezoelectric and ferroelectric properties of the samples. The dielectric behavior of the samples is sensitive to the Ca 2+ content and electric poling. The results demonstrate that the electrical properties of the (Na .47 Bi .47 Ba .06 )TiO 3 lead-free ceramics can be well tuned by varying the Ca 2+ quantity.