Effect of B-site substitution of complex ions on dielectric and piezoelectric properties in (Bi1/2Na1/2)TiO3 piezoelectric ceramics

The effect of B-site substitution of complex ions on dielectric and piezoelectric properties in (Bi1/2Na1/2)Ti1-x(Zn1/3Nb2/3)(x)O-3 (BNTZN-100x) lead-free piezoelectric ceramics was investigated. X-ray diffraction analysis shows that the materials are mono-perovskite phase. The morphotropic phase boundary (MPB) of BNTZN-100x ceramics between rhombohedral and tetragonal locates in the range of 0.5% <= x <= 2.0%. Temperature dependence of dielectric constant shows that these compounds are relaxor ferroelectrics. The compositions near the MPB exhibit relatively high piezoelectric properties. The piezoelectric constant (d(33)) and the electromechanical coupling factor (k(t)) show the maximum values of d(33) = 97 pC N-1 and k(t) = 0.46 at x = 2.0% and x = 1.0%, respectively. The BNTZN- 100x ceramics are good candidate for use as ultrasonic transducer ceramics for high anisotropic with high k(t) value and low k(p) value. (C) 2007 Elsevier B.V. All rights reserved.