Neutron diffraction study of A-site deficient hydrated Perovskites

Transition metal ions can be easily introduced in the B-site of perovskites with general formula ABO3 and exsolved on their surfaces upon reduction, to enhance the catalytic properties in energy applications such as solid oxide cells. Based on the stoichiometries we explored so far, we have good experimental evidence to believe that Ni2+ ions could also be substituted on the A-site of hydrated CaTiO3 and then exsolved upon reduction. Formation of unusual non-stoichiometries with a large proportion of A-site deficiency would be associated with the incorporation of hydroxyl ions in the perovskite structure, and the hydration enhanced proton conductivity. Neutron diffraction study will deepen our understanding of the substitution mechanisms and indeed the indications of protonic conduction allowing for a better design and tailoring of new catalysts and energy materials.