Shrinkage mechanism and enhanced piezoelectric properties of Ta doped 0.94Bi0.5Na0.5TiO3–0.06BaTiO3 lead free ceramics

Abstract

Lead free Bi0.5Na0.5TiO3–BaTiO3 ceramics are well known materials to use in piezoelectric and dielectric applications. To enhance the piezoelectric properties of Bi0.5Na0.5TiO3–BaTiO3 piezoelectric ceramics, 0.94Bi0.5Na0.5TiO3–0.06BaTiO3 ceramics were doped with 0–0.02mol Ta, and then analyzed. The temperature and Ta dependent shrinkage and sintering mechanism were analyzed and compared to optimize their piezoelectric properties. Doping a small amount of Ta improved the piezoelectric charge coefficient from 150 to 170 pC/N. The optimized processing condition for the sintering window to obtain improved piezoelectric properties is very narrow. Therefore, the sintering mechanism for the very narrow sintering window for the Ta doped 0.94Bi0.5Na0.5TiO3–0.06BaTiO3 ceramics has significant meaning for the optimized sintering process to enhance the piezoelectric properties. Piezoelectric and dielectric properties were improved by a large margin with by introducing Ta dopants.