Electrical measurements were carried out upon various ceramics which exhibited a spontaneous relaxor-to-ferroelectric transition. Both the relaxor behavior and the phase transition were found to depend strongly upon the Pb-vacancy content. This was explained in terms of an increase in the ordered domains, and reduced interaction between polar clusters.

O.Bidault, E.Husson, A.Morell: Journal of Applied Physics, 1997, 82[11], 5674-9