Enhanced piezoelectric properties and temperature stability of Bi4Ti3O12-based Aurivillius ceramics via W/Nb substitution

Bi4Ti3O12 (BIT), a typical Aurivillius ceramics with high Curie temperature (T-c similar to 675 degrees C), has great potential for high temperature applications. This work provides an effective method of inducing structure distortion, relieving the tetragonal strain of the TiO6 octahedron and decreasing the concentration of oxygen vacancies to improve the piezoelectricity and temperature stability of BIT ceramics. Bi4Ti2.98W0.01O12 possesses an optimum piezoelectric coefficient (d(33)) of 32 pC/N, a high T-c of 655 degrees C and a large resistivity of 3 x 10(6) Omega.cm at 500 degrees C. The maximum d(33) reported here is approximately quadruple than that of pure BIT ((similar to)7 pC/N). Moreover, the d(33) of W/Nb co-doped BIT and the in-situ temperature stability of the compression-mode sensor present a highly stable characteristic in the range of 25-600 degrees C. These results imply that W/Nb-modified BIT ceramics is a promising candidate for application at high temperatures of up to 600 degrees C.