Crystal distortion and electrical properties of Ce-doped BIT-based piezoelectric ceramics

Cerium (Ce)-modified Bi4Ti2.94W0.03Ta0.03O12 (BITWT) high Curie temperature ceramics (abbreviated as BITWT-xCe) were fabricated by a conventional solid-state sintering method. All BITWT-xCe ceramics had an orthogonal phase, but the structural distortion of the Ce-doped BITWT ceramics was higher than that of BITWT ceramics, which reduced symmetry and improved piezoelectric performance. The relative density (rho(r)) of BITWT-xCe ceramics was greater than 97%. Under the same conditions, the hysteresis loop of BITWT-0.04Ce ceramics had higher saturation than that of BITWT ceramics. The piezoelectric constant (d(33)) was enhanced, and the highest d(33) of 24.7 pC/N at x=0.04 was obtained, which was 25% higher than that of BITWT ceramics (d(33)=19.8pC/N). In addition, the tentative conduction mechanism of BITWT-xCe ceramics was also discussed. Two oxidations (Ce3+ and Ce4+) were present in the Ce-doped BITWT ceramics.