Lead-free (Ba0.85Ca0.15)(Ti0.9Zr0.1)O3–CeO2 ceramics with high piezoelectric coefficient obtained by low-temperature sintering

Lead-free (Ba0.85Ca0.15)(Ti0.9Zr0.1)O3–x%CeO2(BCZT–xCe) piezoelectric ceramics have been prepared by the traditional ceramic process and the effects of CeO2 addition on their phase structure and piezoelectric properties have been studied. The addition of CeO2 significantly improves the sinterability of BCZT ceramics which results in a reduction of sintering temperature from 1540°C to 1350°C without sacrificing the high piezoelectric properties. X-ray diffraction data show that CeO2 diffuses into the lattice of BCZT and a pure perovskite phase is formed. SEM images indicate that a small addition of CeO2 greatly affects the microstructure. Main piezoelectric parameters are optimized at around x=0.04wt% with a high piezoelectric coefficient (d33=600pC/N), a planar electromechanical coefficient (kp=51%), a high dielectric constant (ɛr=4843) and a low dissipation factor (tanδ=0.012) at 1kHz, which indicates that the BCZT–xCe ceramics are promising for lead-free practical applications.