Synthesis and Electrical Properties of Li-modified Bi0.5Na0.5TiO3-BaTiO3 Lead-free Piezoelectric Ceramics

Lead-free piezoelectric ceramics (1-y)Bi0.5(Na1-xLix)0.5TiO3-yBaTiO3 with x=0-0.125 and y=0.02-0.12 were fabricated by a solid-state reaction process, and their dielectric, piezoelectric and ferroelectric properties were investigated. The results show that the addition of Li+ significantly improves the sintering performance and piezoelectric properties of the ceramics. X-ray diffraction (XRD) patterns indicate that the ceramics possess pure perovskite structure. At room temperature, the ceramics provide high piezoelectric charge constant d33 (up to 210 pC/N), high planar electromechanical coupling factor kp (34.5%), large remanent polarization Pr (up to 40 μC/cm2), and low coercive field Ec (3.0 kV/mm), which indicates that (1-y)Bi0.5(Na1-xLix)0.5TiO3-yBaTiO3 is a good lead-free piezoelectric ceramic.