Stabilization effect in ferroelectric materials during aging in ferroelectric state

We report that aging in ferroelectric state results in an increase of reverse transition temperature Tf in both BaTi O3 single crystal and Pb0.84 La0.16 Ti0.96 O3 polycrystal. This indicates that the ferroelectric phase is gradually stabilized during aging below Curie temperature. The evolution of the stabilization with aging time in these two different systems obeys the same kinetic function, but with different relaxation time. This indicates that the stabilization effect of the two systems stems from a common origin. We suggest that the stabilization is due to a short-range ordering of point defects, driven by a symmetry-conforming tendency of point defects.