Kinetic process of the commensurate (δ = 1/8)-incommensurate phase transition in thiourea

Abstract
Careful measurements of the dielectric dispersion and spontaneous polarization of thiourea reconfirmed the existence of the ferroelectric commensurate (δ = 1/8) phase between 177.5K (T 8 1) and 178.1K (T 8 u) under zero bias field. The kinetic process of the field-induced C(δ = 1/8)-IC phase transition was studied by observing the time evolutions of polarization and dielectric constant. The time evolutions of both quantities were similar to those observed for the C-IC transition in Rb2ZnCl4 studied previously, and can be explained by our theory of time evolution of DC lattice for a first-order C-IC transition.