Influence of Lithium and Potassium Doping on Structure and Electrical Characteristics of Li_x(K_yNa_(1-y)_(1-x)(Nb_(0.9)Ta_(0.06)Sb_(0.04)O_3 Lead-Free Piezoelectric Ceramics

摘要

The influence of lithium and potassium doping on the structural and electrical characteristics of Li_x(K_yNa_(1-y)_(1-x)(Nb_(0.9)Ta_(0.06)Sb_(0.04)O_3 lead-free piezoelectric ceramic prepared by the conventional solid-state reaction method was investigated and discussed. X-ray diffraction (XRD) and the scanning electron microscopy (SEM) were carried out to analyze the phases and microstructures of the ceramic specimens, respectively. An impedance analyzer (HP4294A) was used to measure the relative dielectric constant and loss tangent. The electromechanical coupling factor (k_P) and the relative dielectric constant (ε_r) of Li_x(K_yNa_(1-y)_(1-x)(Nb_(0.9)Ta_(0.06)Sb_(0.04)O_3 piezoelectric ceramic for x = 0.06 and y = 0.485 were 1280 and 42.8%, respectively. Finally, the Curie temperature (Tc) of the piezoelectric ceramic was about 340 ℃ and the orthogonal-to-tetragonal phase transition temperature (T_(o-t)) was about 110℃.