Mh. Liang et al., Effect of sintering process on microstructure characteristics of Ba(Mg1/3Ta2/3)O-3 ceramics and their microwave dielectric properties, J EUR CERAM, 21(15), 2001, pp. 2759-2763
Microstructure of Ba(Mg1/3Ta2/3)O-3, BMT, materials were examined using tra
nsmission electron microscopy. Selected area electron diffractions imply th
at the ordering of Mg2+ and Nb5+ cations transforms the BMT materials from
cubic symmetry to P (3) over bar m1 symmetry, which induces the formation o
f polar domains in BMT grains. Large grains contain wavy polar domain bound
aries, dislocations and even the dislocation networks, which are detrimenta
l to the microwave dielectric properties. Presumably, induction of abundant
defects in association with large BMT grains is the prime factor degrading
the microwave dielectric properties of the BMT materials, when they were s
intered at too high temperature. (C) 2001 Published by Elsevier Science Ltd
. All rights reserved.