Enhanced piezoelectric properties of Nb and Mn co-doped CaBi4Ti4O15 high temperature piezoceramics

The properties of CaBi4Ti4O15 (CBT), CaBi4Ti3.95Nb0.05O15 (CBTN) and CaBi4Ti3.95Nb0.05O15 + 0.2 wt% MnO2 (CBTN–Mn) ferroelectric ceramics with bismuth layer structure were studied. Significant enhancement of piezoelectric coefficient was obtained for CBTN–Mn ceramics (d33 = 23 pC/N), being nearly three times that of CBT counterpart (d33 = 8 pC/N). Together with its high Curie temperature (Tc = 790 °C), low dielectric loss (tanδ = 0.2%), high resistivity (ρ = 4.2 × 106 Ω cm at 500 °C) and good thermal stability up to 700 °C, the CBTN–Mn ceramic is a potential material for high temperature piezoelectric applications.