The transverse field effect in the triglycine sulphate ferroelectric

Abstract

The thermodynamic state of a triglycine sulphate crystal, previously exposed to an electric field parallel to the non-ferroelectric c-axis, has been investigated. The frozen ferroelectric c-domains have been observed by a liquid crystal technique and under the scanning electron microscope. Pyroelectric properties and polarization in the non-ferroelectric direction have been investigated. Regions of dipoles that are strongly correlated along the c-direction as well as the clamping of the b-polarization switching have been found to be accompanied by permanent transverse polarization.

Transverse polarization reversal in the triglycine sulphate ferroelectric

“…Therefore, the crystal exhibits also a polarization perpendicular to the ferroelectric b-axis and a remanent polarization P r2 , a parameter of the hysteresis loop P 2 vs. E 2 , is then more or less reduced ( [3] and those cited therein). As follows from the experimental data, the larger transverse polarization P 3 the lower remanent polarization P r2 can be detected.…”

“…However, some experimental results shown in the papers (Refs. [2][3][4] and those cited therein) indicated a potential existence of a permanent transverse polarization, e.g. the polarization perpendicular to the ferroelectric b-axis.…”

Transverse field effect close to the critical point in the TGS ferroelectric

“…Such a decay in time for TGS, triglycine selenate (TGSe) and Rochelle salt ferroelectrics was presented for different electrode systems in our former papers [24][25][26][27]. A series of hysteresis loop decays for TGS is shown in Fig.1.…”

“…Therefore, there are arguments in favour of considering the transverse field effect as occurring due to free electric charges flowing into the crystal [24]. For it is just the high concentration of free charges that may cause a freezing of domains [32,33] and [32,33] with domain walls turned by 90 degrees as well as transverse polarization of the crystal which spontaneously increases while lowering temperature in the zero external electric field (transverse quasi-pyroelectric effect) [25,34] suggest that the nature of the effect under consideration is more complex. In particular, it cannot be understood simply as an electret effect.…”

Observation of dynamics of hydrogen bonds in TGS crystals by means of measurements of pyroelectric currents induced by changes of temperature

“…However, Fugiel studied the pyroelectric properties of TGS along the non-polar c-axis in the TGS 12 . In experiments performed by Fugiel et al, TGS crystals were placed in a constant electric field perpendicular to the ferroelectric axis [12][13][14] . Pyroelectric signals induced by means of the described methods depend on the topography and on the domain pattern of a surface under study.…”