Effects of Donor Doping on Microstructure and Electrical Properties of Bismuth Layer-structured Bi_4Ti_3O_(12) Ceramics

摘要

A study was conducted on the effects of donor dopants, Nb_2O_5 and WO_3, on microstructure and electric properties of Bi_4Ti_3O_(12) (BIT) ceramics. X-ray diffraction patterns of the materials showed a single orthorhombic phase structure. The microstructure results revealed the appearance of plate-like grain. The donor doping decreased the conductivity of BIT by as much as 3 orders of magnitude. The dielectric and ferroelectric properties of doped-BIT materials were also investigated. The decrease in the electrical conductivity allowed the doped samples to be poled to develop piezoelectricity. Thermal annealing studies of the samples indicated the donor-doped BIT were suitable candidate materials for high-temperature piezoelectric applications.