Elastic, piezoelectric, and dielectric characterization of modified BiScO3-PbTiO3 ceramics

The perovskite solid solution system (1x)BiSCO3-(x)PbTiO3 represents an interesting new family of high-temperature piezoelectric materials. Compositions near the morphotropic phase boundary (x similar to 0.64) have been reported to have high Curie temperatures (T-c > 450 degrees C) and good piezoelectric coefficients (d(33) similar to 460 pC/N). In this work, manganese additions were used to improve the high-temperature electrical resistivity and RC time constant of compositions near the morphotropic phase boundary. The addition of manganese was found to shift T-C to slightly lower temperatures (442 degrees C and 456 degrees C for x = 0.64 and x = 0.66, respectively). The piezoelectric activities of the modified materials were found to be reduced slightly due to the hardening effect of manganese; however, the temperature stability and resistivity of the modified materials were significantly enhanced. In this paper we present, for the first time, a complete set of materials constants, including the elastic (s(ij), c(ij)), piezoelectric (d(ij), e(ij), g(ij), h(ij)), dielectric (epsilon(ij), beta(ij)), and electromechanical (k(ij)) coefficients and compare them to both unmodified 0.36BiSCO(3)-0.64PbTiO(3) and PZT5A ceramics.