Asymmetric and modulated magnetic profiles in (LaMnO$_3$)$_{2n}$/(SrMnO$_3$)$_n$ superlattices

ORAL

Abstract

We have determined the magnetic depth profile of MBE-grown ferromagnetic (LaMnO$_3$)$_{2n}$/(SrMnO$_3$)$_n$ superlattices, where $n$ is nominally equal to 3 and 5. Polarized neutron reflectivity measurements reveal the existence of a modulated magnetic structure that repeats with the superlattice period in both samples. For $n$=5, a moment of $\sim$2.6 $\mu_B$/Mn is measured in the LaMnO$_3$ (LMO) layer, while the moment in the middle of the SrMnO$_3$ (SMO) layer is negligible. The magnetization at the interfaces is found to be asymmetric with an enhanced moment residing at the LMO/SMO interfaces but not at the SMO/LMO interfaces. The origin of the magnetic asymmetry at the interfaces is elucidated from comparison with the structural properties determined by x-ray reflectivity and transmission electron microscopy.

*Supported by the U.S. Department of Energy (DOE), Office of Basic Energy Sciences under contract DE-AC02-06CH11357.

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Authors

  • S.J. May

    • MSD, Argonne National Laboratory

  • S.G.E. te Velthuis

    • Materials Science Division, Argonne National Laboratory
    • Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
    • Argonne National Laboratory
    • MSD, Argonne National Laboratory

  • M.R. Fitzsimmons

    • Los Alamos National Laboratory
    • LANSCE-LANL

  • A.B. Shah

    • University of Illinois, Urbana-Champaign

  • J.M. Zuo

    • Univ. of Illinois
    • University of Illinois, Urbana-Champaign

  • X. Zhai

    • Department of Physics, University of Illinois at Urbana-Champaign
    • University of Illinois, Urbana-Champaign

  • J.N. Eckstein

    • Department of Physics, University of Illinois at Urbana-Champaign, Urbana IL 61801
    • Department of Physics, University of Illinois at Urbana-Champaign
    • Univ of Illinois Urbana-Champaign
    • Department of Physics and Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL 61801
    • University of Illinois, Urbana-Champaign

  • S.D. Bader

    • Materials Science Division, Argonne National Laboratory
    • Argonne National Laboratory
    • MSD and CNM, Argonne National Laboratory

  • A. Bhattacharya

    • CNM \& MSD, Argonne National Laboratory
    • Materials Science Division, Argonne National Laboratory, Argonne, IL 60439
    • Argonne National Laboratory
    • MSD and CNM, Argonne National Laboratory