Size effect of precursor particles in W6+-doped CaBi2Nb2O9 high-temperature piezoelectric ceramics

Abstract

High-temperature piezoelectric ceramics face a persistent challenge in simultaneously raising piezoelectric coefficient (d33) and resistivity (ρ) to a practical level. Furthermore, conventional doping strategies exhibit limited effectiveness in further enhancing these properties. Here, we propose a novel approach of reducing precursor particle size in CaBi2Nb1.98W0.02O9 ceramics where WO3 and Nb2O5 were involved as dopant and host matrix, respectively. As compared with microscale precursors, nanoscale counterparts can facilitate diffusion of W⁶⁺-dopant ions into Nb5+-sites, leading to homogeneous elemental distribution, intrinsic structure distortion and suppression of vacancy defects. CaBi2Nb1.98W0.02O9 prepared from nanoscale precursors achieves d33 = 15.6 pC/N and a record high ρ = 4.5×106 Ω‧cm at 600 °C, which outperforms other single-dopant modified CBN-based ceramics. This study paves a practicable approach to obtain high-temperature piezoelectric ceramics for developing vibration-sensors applicable in aircraft engines and nuclear reactors.