Influence of non-stoichiometric ordering on the electrostriction coefficient of lead magnesium niobate lead titanate compositions close to the morphotropic phase boundary
Sm. Gupta et D. Viehland, Influence of non-stoichiometric ordering on the electrostriction coefficient of lead magnesium niobate lead titanate compositions close to the morphotropic phase boundary, J MATER SCI, 34(22), 1999, pp. 5649-5659
The effect of non-stoichiometric ordering on the electrostriction of Pb(Mg-
1/3Nb(2)/3)O-3-PbTiO3 (PMN-PT) compositions (65/35) close to morphotropic p
hase boundary (MPB) has been studied using electrically induced strain and
polarization methods. La was substituted (1 to 10 at %) on the A-site to co
ntrol the degree of B-site cation ordering. The charge imbalance due to La3
+ was compensated by two different mechanisms: (1) creation of B-site vacan
cies, and (2) changing the B-site cation ratio. Electrostriction coefficien
t measurements revealed dependencies on the degree of non-stoichiometric or
dering and the charge compensation mechanism. A high value of the electrost
riction coefficient was found to be accompanied by larger electrically-indu
ced strains and smaller polarizations. In addition, the temperature depende
nce of the electrostriction coefficient was studied. (C) 1999 Kluwer Academ
ic Publishers.