Ferroelectric properties of TGS crystals grown under an intense DC electric field

The application of electric field during crystal growth modifies the ferroelectric properties of triglycine sulphate (TGS) crystals. Scanning electron microscopic examination of freshly cleaved (010) surface shows the presence of some domains tilted with respect to the c-axis. It is suggested that the cause of the onset of domains misaligned with the c-axis is the partial pinning by the field of the rotation of the NH3+ group of the glycine I molecule. The modified domains originate a decrease of the dielectric values, a reduced spontaneous polarization and an increase of the relaxation times. Crystals of TGS grown under field remain in a stable state with modified properties as long as they are not subjected to intense AC fields or annealed above the Curie temperature for more than two cycles. (C) 2002 Elsevier Science B.V. All rights reserved.