Effects of Ag content on the phase structure and piezoelectric properties of (K0.44-xNa0.52Li0.04Agx)(Nb0.91Ta0.05Sb0.04)O3 lead-free ceramics

(K0.44-xNa0.52Li0.04Agx)(Nb0.91Ta0.05Sb0.04)O-3 lead-free piezoelectric ceramics were prepared by normal sintering. The effects of Ag content on the phase structure and piezoelectric properties of the ceramics were mainly studied. These results show that the phase structure undergoes a transition from orthorhombic to tetragonal phase with increasing x from 0.00 to 0.06. The optimum Ag content enhances the piezoelectric properties, and the Curie temperature increases with increasing x. The ceramics with x=0.02 exhibit enhanced electrical properties (d(33)similar to 263 pC/N, k(p)similar to 45.3%, T-C similar to 353 degrees C, epsilon(r)similar to 1478, and tan delta similar to 2.3%) and good aging characteristics. These results show that the ceramic with x=0.02 is a promising lead-free piezoelectric material. (C) 2007 American Institute of Physics.