Enhanced electrical properties in W/Cu co-doped CaBi2Nb2O9 high-temperature piezoelectric ceramics

CaBi2Nb2O9 (CBN)-based high-temperature piezoelectric ceramics with the formula of CaBi2Nb2-x(W3/4Cu1/4)(x)O-9 were prepared via the traditional solid-state reaction method. Both the bulk microstructure and the electrical performance of the W/Cu co-doped CBN-based ceramics were systematically investigated. The results indicated that the W/Cu incorporation into the Nb-site altered the crystal structure, which enhanced the piezoelectricity and resistivity. The ceramic with the composition CaBi2Nb1.96(W3/4Cu1/4)(0.04)O-9 exhibited good performance with a high d(33) (similar to 14 pC/N) and T-C (similar to 939 degrees C). Moreover, the ceramic exhibited a good electrical resistivity (rho) of 4.91 x 10(5) Omega.cm and a low dielectric loss (tan delta) of 0.1 at 600 degrees C. Furthermore, the ceramic that was annealed at 900 degrees C for 2 h presented a d(33) value of 13 pC/N, thus indicating good thermal stability of the piezoelectric properties. All these results confirm that the CaBi2Nb1.96(W3/4Cu1/4)(0.04)O-9 ceramic may act as a potential promising candidate for piezoelectric device applications in high-temperature environments.