Field dependence of the dielectric constant in annealed (001)-oriented Pb(Mg1/3Nb2/3)O3-PbTiO3 single crystals

For annealed (001)-oriented Pb(Mg1/3Nb2/3)O3-PbTiO3 single crystals in the vicinity of morphotropic phase boundary (MPB), two types of field dependence of the dielectric response have been observed. These two types of single crystals showed different P-E (polarization versus field) behaviors. The phenomena can be explained by assemble configurations originated from random fields and symmetry adaptation. The degree of self-organization of domains increases with the increasing PbTiO3 (PT) content. It was deduced that one type of the crystals was in monoclinic composition region, and the other was in orthorhombic or rhombohedral composition regions. The frequency dispersion shoulder of dielectric spectra for the crystals was also discussed.