Synthesis and Characterization of (K_(0.5)Na_(0.5))(Nb_(0.7)Ta_(0.3))O_3 Piezoelectric Ceramics Sintered with Sintering Aid K_(5.4)Cu_(1.3)Ta_(10)O_(29)

摘要

The sinterability and electrical properties of (K_(0.5)Na_(0.5))(Nb_(0.7)Ta_(0.3))O_3 ceramics were investigated as functions of K_(5.4)Cu_(1.3)Ta_(10)O_(29) (KCT) sintering aid content. The (K_(0.5)Na_(0.5))(Nb_(0.7)Ta_(0.3))O_3 ceramics showed a perovskite single phase and a high density at KCT contents ranging from 0.23 to 0.38 mol %. In this composition range, the electrical properties of (K_(0.5)Na_(0.5))(Nb_(0.7)Ta_(0.3))O_3 ceramics were also improved. The planar-mode electromechanical coupling factor (k_p) of (K_(0.5)Na_(0.5))(Nb_(0.7)Ta_(0.3))O_3 ceramics reached 0.44-0.46 in this KCT content range. A high mechanical quality factor (Q_m) of 680 was obtained at a 0.23 mol % KCT content. The (K_(0.5)Na_(0.5))(Nb_(0.7)Ta_(0.3))O_3 ceramics prepared with 0.23 mol % KCT exhibited a field-induced strain of 0.11% at 40 kV/cm and a piezoelectric constant d_(33) of 270 pm/V.