Polarization dependence of the Raman scattering intensities demonstrate that lamellar structures observed in (1x)Pb(Mg1/3Nb2/3)O3-xPbTiO3 (PMN-xPT) single crystals are composed of tetragonal-like and rhombohedral-like layers extending over macroscopic (mm) lengths. Lamellar heterostructures, observed in PMN-0.32PT single crystals are formed in samples cooled under bias electric field applied along pc and then zero-field heated to the vicinity of the so-called depoling temperature TRT. Similar structures were also encountered at ambient conditions. Spatially resolved polarized Raman scattering techniques confirmed that the stripe pattern is due to the coexistence of the phases attached to the opposite sides of the morphotropic phase boundary in the temperature-composition phase diagram.
Macroscopic heterophase pattern in Pb(Mg1/3Nb2/3)O3-PbTiO3 crystals