Novel Orbital Ordering induced by Anisotropic Stress in a Manganite Thin Film

الأصل · EN

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 (=TₘI), and superlattice reflections appear below 140K (=TCO). The electronic structure between TₘI and TCO is identified as A-type antiferromagnetic with the dₓ₂₋y₂ ferroorbital ordering. Below TCO, 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.