Enhanced piezoelectricity and excellent thermal stabilities in Nb–Mg co-doped CaBi4Ti4O15 Aurivillius high Curie temperature ceramics

Abstract Nb–Mg co-doped CaBi4Ti4O15 ceramics were synthesized for potential high temperature piezoelectric applications via the solid-state reaction technique. The influences of Nb–Mg doping level on structure, piezoelectricity and other electrical properties were systematically researched. The XRD, EDS and Raman scattering results confirmed that the doped Nb–Mg ions had successfully diffused into the crystal lattice of CaBi4Ti4O15 ceramic. Co-doping of Nb–Mg enhanced the piezoelectric coefficient d33 effectively without causing significant deterioration on Curie temperature TC. The CaBi4Ti3.9(Nb2/3Mg1/3)0.1O15 ceramic possessed the optimized electric properties with a high d33 value of 24 pC/N accompanied by a high TC value of 787 °C. In addition, this ceramic also exhibited a good thermal stability with d33 keeping 91% of its original value after annealing at 600 °C. All these results suggested that Nb–Mg co-doped CaBi4Ti4O15 ceramic could be a potential candidate for high temperature piezoelectric sensor or detector applications.