Vv. Gladkii et al., POLARIZATION RELAXATION IN A FERROELECTRIC CRYSTAL HAVING DIFFERENT STATES OF THE DOMAIN-STRUCTURE AND SURFACE, Physics of the solid state, 39(11), 1997, pp. 1829-1834
Slow polarization relaxation of a ferroelectric in a weak electric fie
ld is investigated in triglycine sulfate crystals with different state
s of the domain structure and surface. An automated setup is described
that allows one to register relaxation with record accuracy. It is sh
own that under conditions of little change in the ''degree of metastab
ility'' of the structure, the variation of the polarization Delta P wi
th time t follows the law Delta P = C/(1 + t/a)'' in all cases, where
the parameters C, a, and n depend on the state of the structure and th
e surface. We present a phenomenological analysis of the experimental
data based on the assumption that the nuclei are independent and contr
ibute additively to the total polarization of the crystal, and constru
ct spectra of the energy barriers of the domain walls. Aspects of the
transformation of the spectra with variation of the nature of the doma
in structure, depth of surface relief, and magnitude of the external e
lectric field are elucidated. (C) 1997 American Institute of Physics.