Seminars Archive
Jean-Marc Tonnerre
Abstract
Monday, April 2, 2000, 15:30
Seminar Room, ground floor, Building "T"
Sincrotrone Trieste, Basovizza
X-ray resonant magnetic scattering from thin films and multilayers
Jean-Marc Tonnerre
(Laboratoire de Cristallographie, CNRS, Grenoble)
ABSTRACT
The XRMS (X-ray Resonant Magnetic Scattering) is a technique, related
to the XMCD, which exploits the energy tunability and polarisation properties
of synchrotron radiation. Measurements on multilayers and thin films have
been performed in the soft and hard X-ray ranges in the vicinity of the
L2,3 and M4,5 threshold in order to probe 3d, 5d and 4f magnetism, respectively.
Due to the strong resonant enhancement of the magnetic scattering at the
L2,3 edges, we have shown that XRMS may be used to study the interlayer
coupling. By analysing the energy dependence of these peaks, or of the
asymmetry ratio R=(I+-I-)/(I++I-) in the case of ferromagnetic coupling,
it is possible to
recover the dichroic signal, allowing us to determine the orbital and
spin component of the magnetic moment. Alternatively, it is possible to
use a
"standard" XMCD signal to selectively determine the amplitude and the
relative orientation of magnetic moments in a buried alloy thin film
strained on a substrate as it as been done for NiFe/Ag and FeMn/Ir
multilayers. XRMS can also probe the reciprocal space. From the refinement
of the R(E) measured on several Bragg peaks, the reduction of the magnetic
moment at the interface, the description of the induced magnetic moment
extension in a spacer layer can be obtained. Quantitative information can
also be recovered from the angular dependence of R for single magnetic
thin films in TMOKE or LMOKE geometry.
