ABSTRACT
Modern synchrotron X-ray sources providing intense and collimated X-rays of
variable well-defined polarization led to the development of new powerful tech-
niques, which provide new insight into magnetic aspects of the electronic, crystal-
lographic and geometric structure of solids. An important phenomenon used in
the field of magnetism is the X-ray circular magnetic dichroism (XMCD) resulting
from the dependence of the absorption cross section on the magnetization of the
target with respect to the photon helicity. These effects occur for energies close to
an inner shell absorption edge and are intimately related to the spin and orbital
polarization of the unoccupied density of the final states. In the case of the late 3d
transition elements the quantitative determination of magnetic spin and orbital
moments via sum rules in an element-specific manner is possible via a simple
integration of the XMCD profiles. Here we discuss the experimental aspects, a
simple model for the origin of XMCD and typical results. The unique possibility
of X-ray microscopy, which can combine lateral resolution lower than 20 nm1
and time resolution of lower than 20 ps, is described, and its potential to study
magnetization dynamics is demonstrated.
