Piezoelectric properties of (K0.5Na0.5)(Nb1-xTax)O3-K5.4CuTa10O29 ceramics -: art. no. 114105

(K0.5Na0.5)(Nb1-xTax)O-3 (KNNT)-based ceramics have been synthesized via a solid-state reaction. In this study, KNNT-based ceramics were sintered at atmospheric pressure by adding small amounts of sintering aid [0.38 mol % K5.4Cu1.3Ta10O29]. The (K0.5Na0.5)NbO3 (KNN) ceramics which synthesized by using the K5.4Cu1.3Ta10O29 showed "hard" piezoelectric characteristics such as a high mechanical quality factor (Q(m)=1300) and low tan delta (0.4%). The quantitative effects of Ta on the electrical properties of (K0.5Na0.5)(Nb1-xTax)O-3-K5.4Cu1.3Ta10O29 ceramics were also examined. Ta substitution provides "soft" piezoelectric characteristics and a large electrostrictive effect for KNN, which resulted in an improvement in k(p), epsilon(r), strain, and d(33) of KNNT ceramics depending upon the Ta content. Especially, (K0.5Na0.5)(Nb0.7Ta0.3)O-3 showed the maximum strain and d(33) values of 0.11% (at 40 kV/cm) and 270 pm/V (at 30-40 kV/cm), respectively. This strain level is comparable to that of hard Pb(Zr,Ti)O-3 ceramics. (C) 2005 American Institute of Physics.