T. Hauke et al., GLOBAL THERMAL HYSTERESIS OF POLARIZATION REVERSAL IN PURIFIED RB2ZNCL4 CRYSTALS, Journal of the Korean Physical Society, 32, 1998, pp. 904-906
Ferroelectric P(E)-hysteresis loops were recorded in the lock-in phase
of purified Rb2ZnCl4 crystals at two different frequencies f = 100 Hz
and f = 1 kHz. The comparison of results obtained on cooling and heat
ing, respectively, reveales a pronounced thermal hysteresis of the coe
rcive field E-C above the temperature T approximate to 160 K where E-
C(T) changes its slope. Below T, E-c(T) is an unambigious function of
temperature. The analysis of experimental data in terms of a model, w
hich treats sideways shifts of a field independent number of planar, n
early regularly arranged domain walls to be the only mechanism of pola
rization reversal in Rb2ZnCl4 indicates that the thermal hysteresis at
T > T can be attributed to a corresponding hysteresis of the domain
wall density n.