Variation of Morphotropic Phase Boundary with the Bi Deficiency on (Ba, Ce)-co-substituted Sodium Bismuth Titanate

Abstract

We have successfully demonstrated a slight Bi deficiency makes the rhombohedral-tetragonal morphotropic phase boundary (MPB) much more dramatically shift to a lower Ba content in the (Na_0.50Bi_0.50)_1-xBa_xTi_0.99Ce_0.01O₃ [(Ba, Ce)-co-substituted NBT] system than the (Na_0.50Bi_0.50)_1-xBa_xTiO₃ [Ba-substituted NBT] system. Rietveld analysis of (Ba, Ce)-co-substituted NBT revealed that the composition giving the MPB was located at x = 0.44 in restraint of evaporation of sodium and bismuth using the polymerizable complex method, while it was x = 0.12 in the samples of (Na_0.50Bi_0.50-z)_1-xBa_xTi_0.99Ce_0.01O_3-δ with a Bi deficiency of z = 0.03.