The effects of CeO2-doping on piezoelectric and dielectric properties of Bi0.5(Na1 − x − yKxLiy)0.5TiO3 piezoelectric ceramics

CeO2-doped Bi0.5(Na1 − x − yKxLiy)0.5TiO3 lead-free piezoelectric ceramics were prepared by solid-state reaction processes. X-ray diffraction (XRD) data show that the ceramics possess pure perovskite phase. SEM images indicate that a small amount of CeO2 affects the microstructure. The electrical properties of Bi0.5(Na0.725K0.175Li0.1)0.5TiO3 ceramics have been greatly improved by doping of certain amount of CeO2. The temperature dependence of the dielectric constant and dissipation factor reveals that the transition temperature from ferroelectric to anti-ferroelectric phases (Tf) decreases with the addition of CeO2. At room temperature, the ceramics doped with 0.1 wt% CeO2 show quite good performance with high piezoelectric constant (d33 = 220 pC/N), high coupling factor (kp = 39.3%,), enhanced dielectric constant (ɛr = 897) and low dissipation factor (tan δ = 2.0%) at 1 kHz, which indicates that CeO2-doping possesses both effects of increasing the piezoelectric properties and decreasing the dissipation factor of the ceramics.