Increased Curie Temperature Induced by Orbital Ordering in LaSrMnO/BaTiO Superlattices.

Recent theoretical studies indicated that the Curie temperature of perovskite manganite thin films can be increased by more than an order of magnitude by applying appropriate interfacial strain to control orbital ordering. In this work, we demonstrate that the regular intercalation of BaTiO layers between LaSrMnO layers effectively enhances ferromagnetic order and increases the Curie temperature of LaSrMnO/BaTiO superlattices. The preferential orbital occupancy of e(x -y ) in LaSrMnO layers induced by the tensile strain of BaTiO layers is identified by X-ray linear dichroism measurements. Our results reveal that controlling orbital ordering can effectively improve the Curie temperature of LaSrMnO films and that in-plane orbital occupancy is beneficial to the double exchange ferromagnetic coupling of thin-film samples. These findings create new opportunities for the design and control of magnetism in artificial structures and pave the way to a variety of novel magnetoelectronic applications that operate far above room temperature.