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Single crystals of triglycine sulfate (TGS) doped with various L-form amino acids have been prepared. Doping effects on the crystal morphology and the ferroelectric domain structure, and the generation of internal bias field Eb were investigated. For crystals grown from solutions with L-valine, L-leucine, and L-isoleucine, both the morphology and the domain structures were resemble to pure TGS and the generation of Eb was not realized. Doping of L-threonine, L-cysteine, L-asparagine, L-aspartic acid, and L-methionine caused obvious effect on the morphology. The effect on the domain structure and the generation of Eb in these crystals were considerably different from those in L-alanine doped crystals. [ABSTRACT FROM AUTHOR]

Recently a strange temperature dependence of the volume thermal expansion coefficient of TGS crystal has been found in the cryogenic temperature region. Therefore an electric field effect on the simultaneous measurement of the permittivity and the thermal expansion was examined under consideration of difference of a ferroelectric domain structure. The strange feature of the volume thermal expansion coefficient below 10 K was recognized again in the measurement without poling and this feature disappeared in the measurement with poling. This strange thermal expansion without poling might occur because of freezing the interaction between each area in the multi-domain state. [ABSTRACT FROM AUTHOR]

The dielectric dispersion of a triglycine sulfate single crystal has been measured after a prolonged application of the electric field perpendicular to the ferroelectric b axis. As the perpendicular electric field dwarfs the dielectric dispersion, the influence on the dielectric permittivity by the perpendicular electric field looks like the influence by the DC bias electric field parallel to the ferroelectric axis. It is concluded that the perpendicular electric field robustly immobilizes motion of the domain walls which contribute to the dielectric permittivity. [ABSTRACT FROM AUTHOR]

It is confirmed that value of the spontaneous polarization in triglycine sulfate is reduced by a DC electric field perpendicular to its ferroelectric b axis. The reduction is influenced by temperature and by application time, intensity and direction of the perpendicular electric field. The reduced value is maintained for a long time after removing the perpendicular electric field. Charge injected into the crystal seems to be concerned with the reduction of the spontaneous polarization when considering the characteristics of electric conductivity and (de)polarization current. [ABSTRACT FROM AUTHOR]

Abstract: It has been shown that the application of an electric potential to relatively narrow side electrodes of a thin perpendicular parallelepiped Rochelle salt sample plate leads to the disappearance of the hysteresis loop. The effect is permanent and can be observed after the side potential disconnection. Moreover, a reduction of both zero-field longitudinal permittivity maxima at the critical points is visible then. A non-zero remanent polarization and a non-zero coercive field are then able to be observed only at temperatures higher than that of the lower critical point and lower than that of the upper critical one. No corresponding temperature shift in reduced permittivity maxima has been noticed. A transition to below the lower critical point for the next few hours does not lead to restoration of the original properties formerly lost during the side potential application in the ferroelectric phase. Such restoration is possible by annealing the sample above the upper critical temperature. [Copyright &y& Elsevier]