Achievement of high electric performances for bismuth titanate-based piezoceramics via hot press sintering

Bi4Ti3O12 (BIT) ceramic has great potential in high-temperature environment due to its high Curie temperature TC ~ 675 °C. In this work, hot press sintering (HPS) is applied on the 0.01 mol Ce and Nb/Cr co-doped BIT (BCTNC) ceramics to enhancing the low piezoelectric coefficient (d33 < 7 pC/N) and resistivity. Extremely high d33 (~39 pC/N) together with high TC (~672 °C) and high dc resistivity ρ (~1.49 ×107 Ω∙cm at 500 °C) are obtained in HPS samples. The enhancement of piezoelectricity benefits from high density of domain and high poling electric field. Moreover, outstanding thermal stability of piezoelectric constant (d33 ~ 35 pC/N after annealing at 650 °C) and low dielectric loss (tanδ ~ 3.8% at 500 °C) are observed as well. These findings are instrumental in understanding HPS and provide a possible manipulation of crystallized mechanism and domains growing kinetics to enhance piezoelectric performances of BIT based ceramics.