Magnetoresistive La0.67Sr0.33MnO3 Nanowires
C. Li, B. Lie, Z. Luo and C. Zhou
University of Southern California, US
LaSrMnO3 nanowires, core-shell, metal-insulator transition, magnetoresistance
Here, We used a novel non-equilibrium synthesis technique developed by our group to produce La0.67Sr0.33MnO3 nanowires for the first time. These nanowires were synthesized by depositing an epitaxial shell of La0.67Sr0.33MnO3 onto MgO nanowires, thereby rendering single-crystalline MgO/La0.67Sr0.33MnO3 core-shell structures. Transport studies on these nanowires have revealed a remarkable metal-insulator transition at 325 k, accompanied by room-temperature colossal magnetoresistance ~ 10% under a one-Tesla magnetic field. In addition, anisotropic magnetoresistance was observed at room temperature with a 1.4% resistance variation between magnetic fields parallel and perpendicular to the nanowire. Furthermore, polycrystalline La0.67Sr0.33MnO3 have been obtained by tuning the synthesis condition, leading to a low-field magnetoresistance up to 16 % at 0.06 T. This is attributed to the spin-dependent scattering of polarized electrons at the grain boundaries, with underlying physics similar to the giant magnetoresistance. Our study demonstrates the advantages of one-dimensional magnetic oxide nanowires and may lead to novel applications in the near future.
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Nanotech 2005 Conference Program Abstract