Phase development and dielectric responses in PMN-BNT ceramics

(1 - x)Pb(Mg1/3Nb2/3)O-3-x(Bi0.5Na0.5)TiO3 ceramics were prepared by the conventional mixed-oxide method. All compositions show complete perovskite solid solutions and the structure to change from cubic to rhombohedral at x = 0.5. The dielectric constant and dielectric loss tangent were measured as a function of both temperature and frequency. The results indicated a relaxor ferroelectric behavior for all ceramics. The temperature at maximum of the dielectric constant of PMN-BNT ceramics were seen to increase with increasing BNT content. Moreover, the broadest dielectric peak occurs at x = 0.9, which leads to a tnorphotropic phase boundary in this system. (C) 2010 Elsevier Ltd and Techna Group S.r.l. All rights reserved.