Heavy alkaline earth nitride hydrides (AE2NH, with AE = Ca and Ba) are of interest due to their potential suitability as electrolyte materials in a variety of electrochemical devices. A previous study (RB1410181) used an in-situ temperature-conductivity sample environment developed jointly between ISIS and the University of St Andrews. We propose to perform neutron diffraction experiments on AED2 (AE = Ca, Ba) utilising the conductivity sample environment to initially carry out low-levels of nitridation of each compound via the addition of a small amounts of N2 to the gas atmosphere in order to form single phase AED2-x(Ny), before addition of further N2 to form AE2NH. A combination of the structural data with the thermogravimetric and ionic mobility data will be used to build a complete picture of the structure, conduction mechanisms, exchange mechanism and kinetics for these materials.