Memory effect in the triglycine sulphate crystal polarized not parallel to the ferroelectric axis

The experimental results concerning the electric susceptibility chi(22) of the triglycine sulphate (TGS) crystal polarized not parallel to the ferroelectric axis at different temperatures have been shown. The process of partial rejuvenation in the ferroelectric phase has been presented. It has been found that the temperature changes of the slope s = d chi(-1)(22)/dT correspond to step-wise changes of a pyroelectric coefficient p = dP/dT (P = P-2, P-3), where P-2 and P-3 are the longitudinal and transverse polarizations, respectively. An interpretation of temperature dependences of P-2 and P-3 as well as chi(22) of the triglycine sulphate ferroelectric previously exposed to a prolonged transverse electric field has been proposed. It has been concluded that the number of elementary cells containing molecules in metastable states depends on temperature in such a way that some kind of memory effect can be observed. (c) 2005 Elsevier Ltd. All rights reserved.