Pair distribution function analysis of La(Fe_1−xRu_x)AsO compounds

The local structures of La(Fe_1−xRu_x)AsO (0.00≤x≤0.80) compounds were investigated by means of pair distribution function analysis at room temperature; as a result, no phase separation or clustering takes place. Local distortions are no longer correlated beyond ∼15 Å for both pure and substituted samples, indicating that the presence of Ru atoms does not determine a notable variation in the length scale of the local distortion. Different types of short range correlation between Fe and Ru atoms do not produce significant changes in the pair distribution function. - Graphical abstract: Fe–As and Ru–As bond length distributions as obtained by pair distribution function analysis of La(Fe_0.70Ru_0.30)AsO; As atoms (purple spheres) undergo a random shifting around their crystallographic positions (red spheres: Fe/Ru atoms). - Highlights: • No phase separation or clustering takes place in La(Fe_1−xRu_x)AsO solid solutions. • Local distortions are no longer correlated beyond ∼15 Å. • Ru displays a tendency towards local enrichment in the transition metal sublattice