Ce and W co-doped CaBi2Nb2O9 with enhanced piezoelectric constant and electrical resistivity at high temperature

Abstract

Ce and W co-doped CaBi2Nb2O9 ceramics with chemical formula Ca0.96Ce0.04Bi2Nb2-xWxO9 (CCBN-W100x, x = 0–0.07) are fabricated via conventional solid state sintering method, to investigate the effect of W addition on the structure, electrical resistivity, dielectric and piezoelectric properties. A piezoelectric constant d33 of 13.4 pC/N is obtained in CCBN-W2 ceramics, >100% higher than that of pure CaBi2Nb2O9 (d33 = 5.8–6.4 pC/N). Of particular significance is that the electrical resistivity of CCBN-W2 ceramics (ρ = 3.7 × 109 Ω cm at 500 °C) is three orders of magnitude higher than pure CaBi2Nb2O9 (ρ = 2.9 × 106 Ω cm at same temperature). All these properties, together with its low dielectric loss (tanδ = 0.13%) and excellent d33 thermal stability up to 800 °C, merit the CCBN-W2 ceramics for high temperature piezoelectric sensing applications.

Keywords

• Ultra-high temperature ceramics
• Piezoelectric properties
• Aurivillius phase
• Bismuth layered structure
• CaBi2Nb2O9