Structural Disorder and Diffusional Pathway of Oxide Ions in a Doped Pr2NiO4-Based Mixed Conductor

MEM nuclear density analysis from neutron diffraction data measured in situ at 1015.6 °C has indicated the two-dimensional network of curved O2−O3−O2 oxide-ion diffusion paths on the (Pr,La)−O layer in a K2NiF4-type structured oxide-ionic and electronic mixed conductor (Pr0.9La0.1)2(Ni0.74Cu0.21Ga0.05)O4+δ.