Enhanced ferroelectric, piezoelectric and dielectric properties of (1-x) CaBi2Nb2O9-xBaZr0.2Ti0.8O3 high-temperature piezoelectric composite ceramics

Among Aurivillius layer-structured materials, CaBi2Nb2O9 is a best potential candidate for ultrahigh-temperature applications because of its highest Curie temperature of about 940 ?. In this paper, (1-x)CaBi2Nb2O9- xBaZr0.2Ti0.8O3 composite ceramics were prepared by conventional solid-state sintering method. The dielectric results show that the introduction of BaZr0.2Ti0.8O3 not only increases the permittivity of the material, but also reduces its dielectric loss. The optimum electrical properties were obtained in the x = 0.01 sample with piezoelectric coefficient (d(33)) of 15.1 pC/N and high ferroelectric remnant polarization (P-r) of 9.9 mu C/cm(2). Furthermore, the composite samples show good thermal depoling performance, the d(33) of the x = 0.01 sample is 13.8 pC/N, which is about 91% of the initial value after depoling at 800 ?. Therefore, (1-x)CaBi2Nb2O9-xBaZr0.2Ti0.8O3 is one of the candidates for high temperature piezoelectric materials.