Strain-induced local distortions and orbital ordering in Nd_0.5Sr_0.5MnO₃ manganite films

We have performed a detailed study of the long-range and local structure of Nd_0.5Sr_0.5MnO₃ films of varying thicknesses. The detailed nature of the in-plane and out-of-plane d spacings as a function of film thickness was determined. Comparisons between the local structure about Mn and the long-range structure were made. We found that Mn coordination asymmetry exists in thin films and that it is related to orbital ordering. The results yield a confirmation of models of manganite systems, which suggests that biaxial strain enhances electron localization.