Dielectric behaviors of Pb(Fe2/3W1/3)-PbTiO3 relaxors:: Models comparison and numerical calculations

Regarding the dielectric characteristics of the diffusion phase transition (DPT) in ferroelectric relaxor materials, several researchers have provided similar but different laws to explain these phenomenon. These laws, presented by Burfoot and Eiras , have been proven to provide a better explanation, especially the dielectric diffusion phenomenon, of the incomplete DPT materials if compared with the models presented by Smolensky, and Isupov. However, the differences in fitting adaptability and the physical and mathematical meanings between these two laws have never been discussed. In this paper, we analyze these two laws in the (1-x)Pb(Fe2/3W1/3)-xPbTiO(3) [(1-x)PFW-xPT] relaxor system using the statistical regression theory. We find that the laws of both Burfoot and Eiras demonstrate the same adaptability and provide smaller estimation bias on the samples than the models of Smolensky and Isupov, despite the complete or incomplete DPT characteristics. When x is smaller, the samples tend to be complete DPT phenomenon and the estimation bias of Smolensky and Isupov`s models is relatively smaller. However, when the samples show ferroelectric characteristics, the estimation bias will be increased. (c) 2007 American Institute of Physics.