Variations of Morphotropic Phase Boundary and Dielectric Properties with Bi Deficiency on Ba-substituted Na_0.5Bi_0.5TiO₃

Abstract

We synthesized barium-substituted sodium bismuth titanates, (Na_0.5Bi_0.5-z)_1-xBa_xTiO_3-d, without a Bi deficiency (z = 0) and with a Bi deficiency of z = 0.03 by the polymerizable complex method while preventing sodium and bismuth from evaporating. The maximum dielectric constant on the samples without a Bi deficiency (z = 0) was located around a Ba content of x = 0.10. On the other hand, the samples with a Bi deficiency of z = 0.03 indicated the maximum value of dielectric constant at approximately a Ba content of x = 0.06. These Ba contents were consistent with the morphotropic phase boundary (MPB) on each sample with the different Bi deficiencies.