The other hand, the solid solution of NBT

The solid solutions of NBT
with other ferroelectric perovskites have been investigated with the
expectation to develop morphotropic phase boundary (MPB) like systems.  A significant
amount of investigations have been carried out on NBT and its solid
solutions with perovskites like BaTiO3 16, CaTiO3 17,
PbTiO3 18, BiCrO3
19, SrTiO3 20, KNbO3 21, NaNbO3
22. The main objective of these investigations was to achieve the optimum
piezoelectric properties by understanding the structure-property correlations. Among
them NBT- BaTiO3 solid solution is of interest due to high piezoelectric
properties near MPB composition 16. Recently, Dong et al 23 have observed a significant
improvement in the piezoelectric/ferroelectric properties of pure BaTiO3 by making solid solution with BaZrO3
(BZ). Although BZ is paraelectric at room temperature 24, it improves the
piezoelectric/ferroelectric properties of BaTiO3 by shifting the
polymorphic phase boundary near room temperature. On the other hand, the
solid solution of NBT with BZ has hardly been investigated. Hussain et al. 25
have done preliminary investigations on (NBT)(1-x)(BZ)x system and observed optimum piezoelectric
properties near x=0.04 with MPB like behaviour. Recently, Selvamani et al 26
have observed crossover from monoclinic (Cc) to
tetragonal (P4mm) symmetry in the composition range 0.03 < x < 0.05 at room temperature. This structural phase boundary between monoclinic ad tetragonal phase is in concurrence with the observation of MPB like behavior in (NBT)(1-x)(BZ)x system 25. In view of the importance of the MPB, it is imperative to have a detailed understanding of dielectric behaviour. As of our knowledge no investigation has been carried out on the effect of BZ content on dielectric behaviour and phase transition temperature of NBT.  In this paper we have reported the results of the dielectric behaviour of the (NBT)(1-x)(BZ)x system and have examined the correlation between the dielectric anomalies and the structural changes in this system.