Short-range ordering in Pb(B ' B-1/3 ''(2/3))O-3-type relaxer ferroelectrics

The formation of nonstoichiometric 1:1 ordered nanodomains, which promote B -site microcompositional fluctuation, is known to be one of the most-effici ent ways of enhancing diffuse phase transition (DPT) characteristics. A new theory regarding the 1:1 short-range ordering has been developed to accoun t for the observed inability to grow ordered domains beyond the nanometer s cale. The dispersion entropy associated with the formation of negatively ch arged ultrafine domains and the mode of the counter-ion distribution at the domain/matrix interface both have a significant role in controlling the eq uilibrium ordered domain size.