Novel Orbital Ordering induced by Anisotropic Stress in a Manganite Thin   Film
  We performed resonant and nonresonant x-ray diffraction studies of a Nd0.5Sr0.5MnO3 thin film that exhibits a clear first-order transition. Lattice parameters vary drastically at the metal-insulator transition at 170K (=T_MI), and superlattice reflections appear below 140K (=T_CO). The electronic structure between T_MI and T_CO is identified as A-type antiferromagnetic with the d_{x2-y2} ferroorbital ordering. Below T_CO, a new type of antiferroorbital ordering emerges. The accommodation of the large lattice distortion at the first-order phase transition and the appearance of the novel orbital ordering are brought about by the anisotropy in the substrate, a new parameter for the phase control. 
Y. Wakabayashi, D. Bizen, H. Nakao, Y. Murakami, M. Nakamura, Y.   Ogimoto, M. Izumi, K. Miyano and H. Sawa