Photoelectron emission microscopy of magnetic domains in layered magnetic
structures
 
Wolfgang Kuch
Max-Planck-Institut für Mikrostrukturphysik, Weinberg 2, D-06120 Halle,
Germany
 
Magnetic structures consisting of several ultra-thin layers of ferromagnetic,
antiferromagnetic, and non-magnetic materials exhibit many new and interesting
effects.  The fundamental investigation of such layered magnetic structures
calls for a method capable of delivering microscopic magnetic information for
each of the magnetic layers separately.  Photoelectron emission microscopy
(PEEM) with synchrotron radiation is such a technique.  Based on the element
selectivity of x-ray magnetic circular dichroism (XMCD), it allows the
layer-resolved visualization of magnetic domain patterns at surfaces and in
buried layers.  I will show examples of layer-resolved XMCD-PEEM studies of
the magnetic interlayer coupling between two ferromagnetic layers across
non-magnetic and antiferromagnetic spacer layers.  Layer-resolved magnetic
domain images proof the importance of a local magnetic coupling mechanism
related to the magnetostatic stray fields emanating at magnetic domain
boundaries, and reveal the antiferromagnetic spin structure of ultra-thin FeMn
layers.  An interesting aspect of XMCD-PEEM is the possibility for
time-resolved stroboscopic measurements of the magnetization reversal dynamics
exploiting the time structure of the synchrotron radiation.