Slow relaxation of a polydomain ferroelectric in weak electric fields

Polarization relaxation of a polydomain ferroelectric (triglycine sulfate) in weak electric fields has been studied. A phenomenological description of the relaxation process is proposed, which is based on the concept of thermally activated motion of domain walls through energy barriers created by inhomogeneities, and of the existence distribution spectra of relaxation times tau and barrier energies E-g. Possible spectra were constructed from experimental data, and their characteristic parameters were determined for various electric fields E. It is shown that the width of the barrier energy spectrum Delta E-g is practicality independent of E and may probably be considered as a characteristic of crystal inhomogeneity. (C) 1997 American Institute of Physics.