Electric and dielectric studies of the [N(CH3)3H]2CuCl4 compound at low temperature

Abstract The [N(CH 3 ) 3 H] 2 CuCl 4 compound is obtained by slow evaporation at room temperature and is characterized by XRD. It is found to crystallize in the monoclinic system with P2 1 / C space group. Four phase transitions at low temperature are detected by differential scanning calorimetry. The material is characterized by impedance spectroscopy technique measured in the 10 −1 –10 6  Hz frequency and 203–313 K temperature ranges. The dielectric permittivity indicates a ferroelectric–paraelectric phase transition at 293 K. The analysis of Nyquist plots has revealed the contribution of three electrically active regions corresponding to the bulk mechanism, distribution of grain boundaries and electrode processes. The modulus plots are characterized by the presence of two peaks associated with the grain and grain boundaries. The temperature dependence of the electrical conductivity ( σ g ) and AC conductivity ( σ ac ) confirms the phase transitions at T 1  = 226 K, T 2  = 264 K and T 3  = 297 K.