Memory effect in triglycine sulfate induced by a transverse electric field: specific heat measurement

Abstract

The influence of a transverse electric field on the specific heat of triglycine sulfate (TGS) has been studied. The specific heat of TGS has been measured on heating the sample from the ferroelectric to the paraelectric phase after prolonged application of transverse electric field (i.e. perpendicular to the ferroelectric axis). It is shown that the specific heat of TGS can 'remember' the temperature T(s) at which the transverse field was previously applied.

Pyroelectric properties of the triglycine sulphate crystal formerly influenced by a transverse electric field

“…We apparently deal here with a thermally activated effect in which the role of the space electric charge is dominant. An analogous memory effect was obtained during the specific heat measurements [10]. Below the temperature of the transverse field application, the specific heat data obtained before and after this field's action did not differ from each other, similarly as in the case of pyroelectric current density in Figure 4(b).…”

“…In both cases, the driving field can apparently facilitate a transition from one state of the crystal to the other. The experimental results shown in Figure 4(b) and (c) are new examples of memory effects [8][9][10] generated by a transverse electric field. The crystal 'remembers' the temperature T A at which it was formerly exposed to the transverse electric field.…”

“…It should be noted, however, that in the case of the specific heat measurements described in [10], no bias electric field could be applied to the sample just before the measurements so the crystal was apparently in a polydomain state. Summing up the results of the present paper we can state that as follows:…”

“…There are also many other examples of the influence exerted by a transverse electric field on physical properties of uniaxial ferroelectrics. These are quite a new frozen domain structure [6,7], memory effects (permittivity [8], polarization [9], specific heat [10]), suppression of low frequency dispersion [11]and new pyroelectric properties [12].…”

A New Model of Ferroelectric Phase Transition with Neglectable Tunneling Effect*

“…1. Here circles and diamonds are the experimental results of 𝑃s, [34] the reciprocal of static susceptibility (𝜒 −1 s ) of the paraelectric phase, [35] and specific heat (𝑐s + 𝑐 b ) [36] for triglycine sulfate crystal versus temperature 𝑇 , with 𝑐 b being the background irrelevant to FPTs. Solid lines (𝐽 0 = 322.3𝑘 B , 𝛼 = 0.289, 𝛽 = 0.135, 𝜇 = 1.32 × 10 −29 Cm, 𝑁 = 2.80 × 10 27 m 3 ), dash-dotted line (𝐽 0 = 322.3𝑘 B , 𝛼 = 0.301, 𝜇 = 1.32×10 −29 Cm, and 𝑁 = 2.80×10 27 m 3 ), and dotted line (𝐽 0 = 322.3𝑘 B , 𝜇 = 1.32 × 10 −29 Cm, and 𝑁 = 2.80 × 10 27 m 3 ) correspond to the present model, WQL model, and Weiss theory, respectively.…”