Local X-ray Magnetic Circular Dichroism of Fe/Cu(111) using Synchrotron STM

ORAL

Abstract

Synchrotron X-ray Scanning Tunneling Microscopy (SX-STM) combines two of the most powerful materials characterization methods; synchrotron X-ray and STM, and it has a great potential to revolutionize X-ray chemical imaging at the atomic limits. Here, we use SX-STM to study the x-ray magnetic circular dichroism (XMCD) on the Fe L2 and L3 edges of a thin iron film deposited on Cu (111) surface in room temperature. Polarization dependent x-ray absorption spectra have been obtained through a specially fabricated tip that captures photo-electrons. Unlike conventional spin-polarized STM, x-ray excitations provide magnetic contrast even with a non-magnetic tip. Intensity changes in the photo-excited current indicate chemical variations within a single magnetic Fe domain thereby opening up exciting opportunities to study local magnetic properties of materials using the SX-STM-XMCD method.

*DOE: DE-AC02-06CH11357, DOE: DE-FG02-09ER16109, OU-CMSS

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Authors

  • Hao Chang

    • Ohio University / Advanced Photon Source (APS), Argonne National Lab

  • Andrew DiLullo

    • Center for Nanoscale Materials (CNM), Argonne National Lab

  • Nozomi Shirato

    • CNM, Argonne National Lab

  • Marvin Cummings

    • APS, Argonne National Lab

  • Heath Kersell

    • Ohio University / CNM, Argonne National Lab

  • Daniel Rosenmann

    • CNM, Argonne National Lab

  • Dean Miller

    • Electronic Microscopy Center, Argonne National Lab

  • John Freeland

    • APS, Argonne National Lab

  • Saw-Wai Hla

    • Ohio University / CNM, Argonne National Lab

  • Volker Rose

    • APS, Argonne National Lab