Enhanced electrical properties in Nd and Ce co-doped CaBi4Ti4O15 high temperature piezoceramics

Lead-free piezoelectric material with excellent piezoelectric properties and high Curie temperature is necessary for practical applications. In this work, (Nd, Ce) co-doped CaBi4Ti4O15 (CBT) ceramics were prepared by the conventional solid-state reaction technique. The effect of (Nd, Ce) co-doping on the structure and resulting electrical properties of CBT ceramics was systematically investigated. The optimized comprehensive performances were obtained at x = 0.075 with a large piezoelectric coefficient (19 pC/N), a low dielectric loss (0.073%) and a high Curie temperature (794 °C). More importantly, the ceramic also maintained a very high resistance and a low dielectric loss even at 400 °C (ρ = 2.5 × 108 Ω cm, tan δ = 1.96%) and the d33 showed no sign of waning after annealed at 400 °C, which shows great potential for high temperature piezoelectric device applications. Related mechanisms for the enhancement of electrical properties were discussed.