Measurements of the elastic (Young's) modulus, mechanical losses and d.c. e
lectrical conductivity as a function of the temperature in Aurivillius type
structure ferroelectric ceramics have been performed. The results suggest
that the anomalies appearing in macroscopic complex elastic modulus and ele
ctrical conductivity near the temperature of 300 degrees C, do not correspo
nd to a ferro- paraelectric or ferro-ferroelectric phase transition. These
anomalies could be caused by a change in the defect structure coming from u
nstable Bi3+ cation. (C) 1999 Elsevier Science Limited. All rights reserved
.