Effects of growth conditions on the domain structure and dielectric properties of (1 - X)Pb(Sc_1/2Nb_1/2)O₃- xPbTiO₃ single crystals

The studies of the (1 - x)Pb(Sc_1/2Nb_1/2)O ₃-xPbTiO₃ (PSN-PT) single crystals reveal that the chemical and physical properties of the materials are affected by the growth conditions. By the measurements of the dielectric constant as a function of temperature upon cooling, it is found that crystals grown from the same charged stoichiometric composition (x = 0.425), but under different flux environments (i.e. the composition of flux and the flux to PSN-PT ratios are varied), show anomalies (i.e. phase transitions) at different temperatures. This phenomenon is attributed to the complex local chemical structure of the PSN-PT solid solution single crystals with B-site random occupancy of three different cations (Sc³⁺, Nb⁵⁺ and Ti⁴⁺). The dielectric and domain structure of the PSN-PT crystals with composition near the morphotropic phase boundary (MPB) are investigated, showing much more complex situations compared with Pb(Sc_1/2Nb_1/2)O₃.