Investigating the Electromechanical properties of Ce-doped (Ba0.85Ca0.15)(Zr0.1Ti0.9)O3 lead-free piezoceramics for actuator applications

In this work, lead-free [(Ba0.85,Ca0.15)1-xCex/2](Zr0.1,Ti0.9)O3 (BCCexZT) piezoceramics were synthesized via solid state ceramic processing and the effects of Ceria, as a donor dopant, on dielectric, ferroelectric and electromechanical properties was investigated. The microstructure, phase composition, and local structure were investigated by scanning electron microscopy, X-ray diffraction, and Raman spectroscopy. Electron paramagnetic resonance spectroscopy was used to study the defects and better understand the mechanism of the increase in the electromechanical properties. In [(Ba0.85,Ca0.15)1-xCex/2](Zr0.1,Ti0.9)O3 samples, the highest d33* value of 1150 pm/V was obtained for x=0.1at the lowest sintering temperature of 1350 °C, which was much higher than pure BCZT (780 pm/V). This increase in electromechanical properties would be related to the easier movement of domain which induces larger field-dependent strains in Ce-doped samples. The EPR signals indicated the existence of cation vacancies and confirmed the soft piezoelectric nature of BCCe0.1ZT samples. The considerable increase in large signal coefficients occurred in a lower sintering temperature than that of pure BCZT and this makes BCCexZT a good candidate for room temperature actuator application.