Enhanced piezoelectric properties of (Bi,Na)TiO3 -(Bi,K)TiO3 ceramics prepared by two-step sintering process

Abstract

To enhance the piezoelectric properties and lower the sintering temperature of lead-free (Bi,Na) TiO3-(Bi,K) TiO3 ceramics, two-step sintering process was employed and investigated. As a representative lead-free piezoelectric materials, (Bi,Na) TiO3-(Bi,K) TiO3 has been selected for the two-step sintering process. The two-step sintering process can be the advisable fabrication process, especially for the case of volatile materials were contained. The two-step sintering process can also minimize the evaporation of volatile components. By lowering the sintering temperature and increasing the sintering time in the second step, grain size was enlarged and density was improved. By optimizing the holding time from the 0.80Bi0.5Na0.5TiO3-0.20Bi0.5K0.5TiO3 ceramics, improved bulk density of 5.81 g/cm3, piezoelectric charge coefficient of 170 pC/N and dielectric constant of 1471.29 were obtained. As a result, piezoelectric and structural properties can be enhanced. In this research, we will report the enhanced crystalline and piezoelectric properties of (Bi,Na) TiO3-(Bi,K) TiO3 ceramics prepared by the two-step sintering process.