V. Kapustianik et al., ANOMALOUS DIELECTRIC BEHAVIOR OF NH2(CH3)(2)AL(SO4)(2)CENTER-DOT-6H(2)O CRYSTALS IN THE FERROELECTRIC PHASE, Journal of physics. Condensed matter, 9(3), 1997, pp. 723-733
The temperature- and frequency-dependent dielectric susceptibility par
allel to the ferroelectric axis of NH2(CH3)(2)Al(SO4)(2).6H(2)O crysta
ls was studied in the ferroelectric phase. The dispersion correspondin
g to a critical slowing down of the thermal dipole relaxation was obse
rved in the vicinity of T-c in the frequency range 1-10 MHz. Besides,
a dispersion which is related to the dipole reversal within the domain
walls was found at lower frequencies. The latter is much more pronoun
ced in the deuterated sample and is thought to be connected with the d
ynamics of hydrogen bonds.