Molecular Cation Motion in the (NH3NH2)Mg(HCO2)3 Frameworks

Ferroelectrics, which have permanent and switchable charge polarisation, have many applications including memory storage and energy harvesting. There is growing interest in ferroelectric materials built from extended frameworks comprising metal centres bridged by organic ligands where the polarisation arises from charged molecules in the pores of these materials. Amongst such compounds (NH3NH2)Mg(HCO2)3 is especially interesting, having been reported to have ferroelectric properties that are potentially useful across a wider range of temperatures. Such relaxor ferroelectric properties are usually caused by mechanisms not possible in this case. We will investigate the dynamics of the proton movement to support our recent NMR studies, and whether the protons are migrating within or between the NH3NH2 molecules, to understand the origins of the functional properties of this material.