Synthesis, characterization, thermal analysis and electrical properties of (NH4)2M(SO4)2·6H2O (M = Cu, Co, Ni)

Abstract With the aim to prepare new materials suitable for the storage energy field, we have reported the elaboration, by the slow evaporation method at room temperature, of Tutton’s salts crystals with chemical formula (NH 4 ) 2 M(SO 4 ) 2 ·6H 2 O (M = Co, Ni, Cu) and denoted as NHMS6. X-ray diffraction (XRD) shows a simple monoclinic system for the obtained phases with the space group P 2 1 / a (Z = 2). Visible (Vis) spectroscopy presents the absorption bands of transition metal M 2+ in an octahedral environment [M(H 2 O) 6 ] 2+ . Thermogravimetry (TG-DTG) analysis shows difference in dehydration scheme from one material to another. Electrical properties of anhydrous materials were studied by spectroscopy impedance complex (SIC) in different temperature ranges depending on the compound. Resistance, conductivity values and conduction mechanism within the materials are determined and discussed. These materials can be considered as good candidates in the storage energy application as M-batteries.