Polarization Dynamics in compositions of PMN-PT near the Morphotropic Phase Boundary

Pb(Mg₁/₃Nb₂/₃)_(1-x)–(PbTiO₃)_x (PMN-PT), with a concentration of PT, x < 0.33, is a relaxor ferroelectric that exhibits unusually strong piezoelectric and pyroelectric coefficients, which have been attributed to the formation of short-range polar regions. The microscopic origins of such short-range polar order and their coexistence and competition with long-range polar order remain unclear. The application of an electric field in the (111) direction can induce macroscopic polarization in PMN-PT, generating a field-induced ferroelectric phase transition. We applied electric fields in different regimes (field cooling–field heating and zero-field cooling) to study the properties of the induced polar state and how it depends on the electrical prehistory of the sample. We found some new, interesting properties of the induced polar state, which significantly differ from the published observations of PMN-PT samples with low Ti concentrations. We believe that short-range polar regions in PMN-PT can act as precursors of polarization capable of storing the sample’s phase transition history. However, we also found that slower cooling rates or intermediate aging steps can hinder this behavior, delay the field-induced ferroelectric phase transition, and decrease its onset temperature.