Enhanced piezoelectricity in lead-free BCZT piezoceramics for sensor applications

Abstract

Piezoelectric properties of the recently developed lead-free (Ba0.85Ca0.15)(Ti0.9Zr0.1)O3 (BCZT) ceramics has been improved by suitable additives. In the present study, different tetravalent additives (SiO2, GeO2, MnO2 and CeO2) have been added to BCZT ceramics and their effect on phase structure and piezoelectric properties of BCZT ceramics have successfully been investigated. X-ray diffraction spectra of BCZT-0.08 wt.% XO2 (X = Si4+, Ge4+, Mn4+, and Ce4+) ceramics showed the diffusion of additives into the BCZT lattice and form a single-phase perovskite structure. SEM micrographs showed dense microstructure with homogeneous distribution of grains of size ∼ 10 - 13 μm. CeO2 added BCZT ceramics showed high remnant polarization Pr ∼ 12 μC/cm2 and a low coercive field Ec ∼ 1.6 kV/cm compared to other BCZT-0.08 wt.% XO2 (X = Si4+, Ge4+ and Mn4+) ceramics. Excellent piezoelectric properties (d33 ∼ 675 pC/N, g33 ∼ 14 mV.m/N, and kp ∼ 60%) were observed for the CeO2 added BCZT ceramics, which is the highest value reported so far for any lead-free piezoceramics. Hence, CeO2 added BCZT ceramics could be a potential lead-free piezoelectric material for sensor applications.