ELECTRICAL-CONDUCTIVITY, DIELECTRIC-PROPERTIES AND PHASE-TRANSITION IN ETHYLENEDIAMMONIUM SULFATE SINGLE-CRYSTALS

D.C. and a.c. electrical conductivities, dielectric constant and dielectric loss factor in single crystals of ethylenediammonium sulphate, (H3NCH2CH2NH3)(SO4), have been measured axiswise as a function of temperature. Anomalous variations in all the above properties at 480 K indicate the occurrence of a phase transition in the above material at this temperature. The existence of such a phase transition is also confirmed by DSC measurements. Electrical conductivity results are analysed and the activation energies of conduction at different temperature regions have been evaluated from the log-sigma vs 10(3) T-1 plot. Possible mechanisms for the electrical conduction process are discussed, the available results being in favour of a proton transport model.