Mixed-anion compounds such as lanthanum oxyfluorides are increasingly attractive as 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 local structure, local anion/cation ordering and related anion migration pathways is determined. Here we focus on the lanthanum oxyfluorides and wish to probe the temperature evolution of local structure, local anion/cation ordering, as well as the evolution of interstitial anions, which will provide insight into the anion transport pathways.