Effect of Tantalum ion doping on the structure and electrical properties of Bi 3 Ti 1.5 W 0.5 O 9 -Bi 4 Ti 3 O 12 intergrowth bismuth-layered ceramics

Bi 7 Ti 4.5- x Ta x W 0.5 O 21 (BTW-BIT- x Ta, x = 0.00, 0.05, 0.10, 0.15, 0.20, 0.30) intergrowth bismuth-layered ceramics were fabricated by traditional solid-phase method. The effects of Ta 5+ ion doping on the structure and morphology of BTW-BIT ceramics were investigated by measuring XRD and SEM Photos. It indicated that octahedral distortion was increased with the introduction of Ta 5+ ion, giving rise to enhancing Curie temperature and ranging from 689 °C to 721 °C. By means of analysis of the dielectric, impedance and ferroelectric, it was concluded that oxygen vacancies of samples were reduced due to donor ion Ta 5+ substituted for ion Ti 4+ at B-site. The decreased oxygen vacancies lessened the dielectric loss, improved the insulating properties of the samples, and made the electrical performances better. BTW-BIT-0.10Ta had the optimal electrical performances with a high d 33 of 15.3 pC/N (more than twice that of BTW-BIT ceramic), a high Curie temperature T c of 705 °C and a good thermal stability, indicating a potential application in the high-temperature field.