Evolution of structural distortion and electric properties of BTN-based high-temperature piezoelectric ceramics with tungsten substitution

The Bi2.93Ce0.07TiNb1-xWxO9 (BCTNW-100x, x = 0-0.06) high-temperature piezoelectric ceramics were fabricated via a conventional solid-state reaction processing. The influence of tungsten substitution for niobium in the crystal structure of Bi3TiNbO9-based ceramics was studied in detail. The crystal structure analysis revealed that the introduction of W6+ enhanced the octahedral tilt angle along the a axis, which resulted in an optimal piezoelectric property (d(33) = 19.2 pC/N) at x= 0.02. While the structural distortion of BCTNW-100x ceramics became weak with W content further increasing, which made the thermal stability of BCTNW-100x ceramics better. When annealing temperature elevated to 700 degrees C, the d(33 )value of BCTNW-6 ceramic still remained 92% of its initial value, indicating good thermal stability. Furthermore, the dc conduction mechanism of the ceramics was studied. The oxygen vacancies played an important role in dc conduction mechanism at low temperature and the main conduction mechanism at high temperature was intrinsic conduction. (C) 2019 Elsevier B.V. All rights reserved.