Synthesis and piezoelectric properties of lead-free piezoelectric [Bi_(0.5)(Na_(1-x-y)K_xLi_y)_(0.5)]TiO_3 ceramics

摘要

A new group of lead-free piezoelectric ceramics, [Bi_(0.5)(Na_(1-x-y)K_xLi_y)_(0.5)]TiO_3, were invented. These ceramics were prepared by conventional ceramic sintering technique. The results of X-ray diffraction (XRD) data show that the ceramics possess almost pure perovskite phase with a little unknown phase when y <= 0.20. The measurements of dielectric and piezoelectric properties reveal that the ceramics with high amount of K~+ and low amount of Li~+ provide relatively high piezoelectric charge constant d_(33) (up to 180 pC/N) and high planar electromechanical coupling factor k_p (up to 35.0 percent). The fabrication technique for these ceramics is stable. It is obvious that the ceramics can be used in practical applications.