Structural, magnetic, and electronic properties of (110)-oriented epitaxial thin films of the bilayer manganite La1.2Sr1.8Mn2O7 -: art. no. 142508

We have synthesized (110)-oriented epitaxial thin films of the bilayer (n=2) manganite, La1.2Sr1.8Mn2O7, with the metallic/ferromagnetic a-b planes lying perpendicular to the substrate surface and the c-axis aligned in the plane of the film. X-ray diffraction and transmission electron microscopy confirm the alignment of the a-b planes along the [1 (1) over bar0] substrate direction. The films consist primarily of the n=2 phase with a minor component of the n=1 (La,Sr)(2)MnO4 and n=infinity (La,Sr)MnO3 phases. A resistivity maximum coincides with a ferromagnet/paramagnet transition at a reduced T-c similar to 90 K (versus 120 K for bulk), indicative of the effects of epitaxial strain. The films display similar anisotropic properties to their bulk counterpart with the magnetically easy direction confined to the a-b planes and 20-200 times lower resistivity for current flowing along the a-b planes compared to the c-axis. (C) 2005 American Institute of Physics.