Sy. Kang et Jj. Kim, DIELECTRIC-DISPERSION AT THE ZERO-FIELD LOCK-IN TRANSITION IN THIOUREA CRYSTAL, Physical review. B, Condensed matter, 47(18), 1993, pp. 12263-12265
Splitting of the dielectric-constant peak at T congruent-to 177.1 K wa
s observed in the high-frequency measurements at zero bias field in th
e very narrow range of temperature across the 1/8 lock-in transition i
n thiourea. This frequency-dependent splitting of the dielectric-const
ant peak associated with the 1/8 lock-in transition could be explained
in terms of temperature-dependent relaxation time.