Deciphering the piezoelectric and conductive mechanisms of Nb-doped Bi3Ti1.5W0.5O9 high-temperature piezoelectric ceramics

The study utilizes Bi 3 Ti (1.5- x ) Nb x W 0.5 O 9 (BTW- x Nb, x =0.00, 0.01, 0.02, 0.04, 0.06) bismuth layered piezoelectric ceramics synthesized via a conventional solid-phase reaction process. This is the study to investigate the impact of B-site Nb ion doping on the structural and electrical properties of BTW- x Nb ceramic. The results show that all ceramics have a single bismuth layer structure, with reduced lattice distortion according to Rietveld refinement findings. The presence of oxygen vacancies in the ceramic is the main factor that affects the high temperature conductivity of the samples. The XPS results, the increase in the activation energy of AC and DC conductivity confirm that doping with Nb 5+ ions reduces oxygen vacancy concentration. The ceramics with the highest overall electrical performance are the BTW-0.02 Nb ceramics. Notably, the DC resistivity at 500 °C was enhanced from 9.16 × 10 5 Ω·cm ( x = 0.00) to 8.24 × 10 6 Ω·cm. The T C was enhanced from 730 °C(undoped) to 743 °C. At 500 °C, tanδ decreases from 21.1 % to 8.2 %. The ceramic's increased resistivity increases the polarization voltage, resulting in more complete polarization. The d 33 is increased from 7.5 pC/N (undoped) to 13 pC/N. Furthermore, the piezoelectric properties remain stable up to 700°C, suggesting that the material has considerable potential for use at elevated temperatures. • The effects of B-site donor doping on the crystal structure, conductivity mechanism and electrical properties of Bi 3 Ti 1.5 W 0.5 O 9 ¬ ceramics were studied in detail. • B-site Nb ion doping reduces the oxygen vacancy concentration and significantly enhances the resistivity. • The properties investigated in this work are comprehensively improved. • For further research into the system, this work is a good guide.