Ultrahigh-temperature piezoelectric polycrystalline ceramics: dramatically enhanced ferroelectricity, piezoelectricity and electrical resistivity in Ca<sub>1−3<i>x</i></sub>Bi<sub>2+3<i>x</i></sub>Nb<sub>2−<i>x</i></sub>Mn<i><sub>x</sub></i>O<sub>9</sub>
Changbai Long, Wei Ren, Kun Zheng, Huiqing Fan
Abstract
Among Aurivillius-phase ferroelectric ceramics, CaBi2Nb2O9 is considered as the best candidate with potential applications in ultrahigh-temperature piezoelectric devices due to the highest Tc (∼940 °C). This paper reports that BiMn co-substitution at A and B sites gives rise to dramatic enchantments in ferroelectricity, piezoelectricity, and electrical resistivity of CaBi2Nb2O9 ceramics. The optimum composition (Ca0.97Bi2.03Nb1.99Mn0.01O9) with a Tc of 953 ± 3°C shows a high ferroelectric remnant polarization (Pr), field-induced strain (S33), piezoelectric activity d33 and $d_{33}^\ast $ with values of ∼11.1 µC/cm2, 4.9 × 10−4, 20.8 and 26.1 pC/N, respectively, which are about two to three times those of CaBi2Nb2O9.