X-ray photoemission electron microscopy (X-PEEM) can image the magnetic ground state configuration
of large arrays of nanoscale magnetic elements with varying shapes, sizes and magnetostatic interactions
between elements. Magnetic contrast is obtained from the asymmetry in photoelectron yield for opposite
helicities of CP x-rays. Magnetic images of square permalloy ring arrays where the elements are touching
(left) or non-touching (right) are shown. The samples were saturated in the beam direction (horizontal)
and imaged in remanence at the Ni L3 resonance (852.7 eV). While vortex states are found in separated rings
they are suppressed in touching rings. Those are mostly saturated, and some show frustrated states. Whereas
magnetostatic interactions can alter the ground state a small separation makes the structures independent.
[D.R. Lee & D. Keavney(APS),V. Metlushko(UIC)]
Local Contact: David Keavney (
keavney@aps.anl.gov)
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