Dielectric and Dilatometric Properties of NH(CH$\text{}_{3}$)$\text{}_{3}$CuCl$\text{}_{3}$·2H$\text{}_{2}$O Low Dimensional Ferroics

On the basis of dilatometric and dielectric investigations of NH(CH$\text{}_{3}$)$\text{}_{3}$CuCl$\text{}_{3}$·2H$\text{}_{2}$O crystals the earlier unknown phase transition with considerable temperature hysteresis was found at T$\text{}_{1}^{c}$=198 K and T$\text{}_{1}^{h}$=223 K, respectively, in cooling and heating runs. Existence of the characteristic dielectric dispersion was revealed within the high-temperature phase. It corresponds to the single dielectric relaxator below 250 K as well as to co-existence of two relaxators above this temperature. The determined values of the activation energy and relaxation time are characteristic of the co-operative reorientation of the trimethylammonium cation (high-frequency relaxator) whereas the combined reorientation motions of the CuCl$\text{}_{2}$·2H$\text{}_{2}$O chains would be responsible for the low-frequency relaxation process. It was found that the above mentioned quasi-Debye type processes are involved into the mechanisms of the protonic conductivity.