Switchable dielectric behavior induced by a disorder–order structural phase transition in (C3H12N2)2(HSO4)2[Mn(H2O)4(SO4)2

Abstract

The inorganic–organic hybrid compound (C3H12N2)2(HSO4)2[Mn(H2O)4(SO4)2] (1) was synthesized under slow evaporation conditions. Differential scanning calorimetry (DSC) measurement indicated that compound 1 undergoes a reversible phase transition at 278K with a hysteresis width of 3K. Two-temperature single crystal X-ray diffraction data showed that the unit cell contains the (C3H12N2)2+ cation, with discrete [Mn(H2O)4(SO4)2]2− and HSO4− anions. The unit cell volume of 1 become double on decreasing the temperature. The disorder–order transformation of the C atoms of the (C3H12N2)2+ cation may drive the structural phase transition. The dielectric permittivity of compound 1 can be switched between two states, which could be used in switchable dielectric devices.