Crystal Structure, Piezoelectric and Dielectric Properties of (Li, Ce)4+ Nb5+ and Mn2+ Co doped CaBi4Ti4O15 High Temperature Ceramics
Bismuth layered structured ceramics Ca0.85(Li,Ce)0.075Bi4Ti4 xNbxO15 0.01MnCO3 were prepared by the conventional solid state reaction method. The evolution of microstructure and corresponding electrical properties were studied. All the samples presented a single bismuth layered structural phase with m 4, indicating that (Li, Ce)4+ Nb5+ and Mn2+ adequately enter into the pseudo perovskite structure and form solid solutions. It was found that Ca0.85(Li,Ce)0.075Bi4Ti3.98Nb0.02O15 0.01MnCO3 (CBTLCM 0.02Nb) ceramics possess the optimum electrical properties. The piezoelectric coefficient d33, dielectric constant er, loss tand, planar electromechanical coupling factor kp and Curie temperature TC of CBTLCM 0.02Nb ceramics were found to be ~19.6 pC/N, 160, 0.16% 8.1% and 767degC, respectively. Furthermore, the thermal depoling behavior demonstrates that the d33 value of x 0.02 content remains at 16.8 pC/N after annealing at 500degC. These results suggest that the (Li, Ce)4+ Nb5+ and Mn2+ doped CBT based ceramics are promising candidates for high temperature piezoelectric applications.
Journal of Electronic Materials