Order-Disorder Reactions in the Ferroelectric Perovskites
نویسندگان
چکیده
The perovskites Pb(SclpNblp)O, and Pb(SclpTalp)O, can be obtained in a disordered state by means of a synthesis a t high temperature (1 250 to 1600 "C). Ordering of the trivalent and pentavalent ions occurs during annealing a t lower temperatures. The kinetics of this ordering process are investigated by means of X-ray diffraction, dielectric polarisation, and DSC measurements. The ordering process proceeds via a nucleation-growth process and the average diameter of the ordered domains as a function of the anneeling time is determined by X-ray line broadening. Disordering experiments are carried out on Pb(Sc1pNblp)O3 and an orderdisorder transition temperature of 1210 "C is yielded.
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