Electrical properties and thermal stability of Na0.5Bi4.5−x(La0.5Ce0.5)xTi4O15 Aurivillius ceramics

Lead-free piezoelectric ceramics, Na0.5Bi4.5−x(La0.5Ce0.5)xTi4O15 (LCNBT-x, x=0, 0.1, 0.15, 0.2 and 0.3), were synthesized by a conventional solid-state reaction. Structural and electrical properties of LCNBT-x ceramics were systematically investigated. X-ray techniques analysis suggested that the substitution formed layered perovskite structure. Plate-like morphologies for the grains were clearly observed for all the samples, which are characteristic for layer-structure Aurivillius compounds. High piezoelectric coefficient of d33~25 pC/N and Curie temperature Tc~644 °C were obtained for the samples at x=0.15. Thermal annealing studies indicated that the relative d33 of all samples keep up over 90% even if annealing temperature increased to be 430 °C, demonstrating the ceramics are the promising candidates for high-temperature applications.