Effect of Nb doping on the microstructural and electrical properties of the PZT ceramics

The aim of this study is the determination of the effect of the aliovalent Nb5+ doping in PZT (65/35) based bulk materials in their microstructural evolution and their electrical properties. The Nb content was chosen in the range 0-10 mol%. These materials were prepared using the conventional way. The calcined mixture was found to be monophasic perovskite powder. The characteristics of the as-formed powder were described and related to the microstructural ones in the sintered material, namely the grain size evolution and the porosity elimination. Nb addition was found to alter significantly the parameters of the crystal cell, and so, the dielectric and ferroelectric properties. The electrical properties were compared with those of common PZT and PLZT materials; As in the case of PLZT (x/65/35), several Nb containing compositions show diffuse phase transition (DPT) characteristics. The Nb content is also leading to softening of the PZT. However, the ferroelectric and dielectric behaviour kept strongly dependent on the microstructural characteristics. (C) 2001 Elsevier Science Ltd. All rights reserved.