Piezoelectric and dielectric properties of 0.98(Na0.5K0.5)NbO3-0.02Ba(ZrxTi(1-x))O-3 ceramics

Abstract

Lead-free 0.98(Na0.5K0.5)NbO3-0.02Ba(ZrxTi(1-x))O-3(0.98NKN-0.02BZT) ceramics with Zr contents were fabricated by a conventional mixed-oxide method. The results indicate that the Zr/Ti ratio significantly influences the structural, piezoelectric, dielectric, and ferroelectric properties of 0.98NKN-0.02BZT ceramics. For the 0.98NKN-0.02BZT (x = 0) ceramics sintered at 1090 degrees C, the bulk density increased as the Zr contents decreased and showed a maximum value at x = 0. The Curie temperature of the 0.98NKN-0.02BZT ceramics slightly decreased as the Zr contents increased. The dielectric constant, piezoelectric constant, and electromechanical coupling factor of samples were maximized at x = 0, which might be due to the increase in density. A high d(33) = 194 pC/N, k(p) = 38% were obtained for the 0.98NKN-0.02BZT ceramics sintered at 1090 degrees C for 4 h. (C) 2012 Elsevier Ltd. All rights reserved.