Layered oxides are increasingly attractive as electrode materials in energy technology applications, such as fuel cells, electrolysers and permeation membranes. As the structures become more complex it is essential that a detailed understanding of the evolution of any cation ordering and related anion migration pathways is determined. Here we are focussed on the Ruddlesden-Popper series of oxides with a mixed A site (La and Pr)and wish to probe the temperature evolution of cation ordering, as well as the evolution of oxygen vacancies, which will provide insight into the oxygen transport pathways.