Seminars Archive
Evgueni Meltchakov
Abstract
Thursday, April 5, 2000, 14:00
Seminar Room, ground floor, Building "T"
Sincrotrone Trieste, Basovizza
Magnetic multilayers for polarization analysis in soft X-ray range
Evgueni Meltchakov
(Multilayer Technology Laboratory, Sincrotrone Trieste)
ABSTRACT
The exact knowledge of the polarization state of synchrotron radiation
is essential for a quantitative understanding of various phenomena in physics,
chemistry, biology, material science, etc. However, the performance of
available non-magnetic optical elements for polarimetry degrades significantly
in the soft x-ray range due to strong absorption and the real structure
effects. The techniques of magnetic circular dichroism (MCD) and x-ray
resonant magnetic scattering (XRMS) have been used to investigate the magneto-optical
effects resonantly enhanced in the vicinity of the 3d absorption edge of
rare-earth (RE) elements and the 2p edge of transition metals (TM). The
dichroic signal from the Gd/Fe and Gd/Co multilayers at room temperature
was measured as a function of the degree of circular polarization in order
to calibrate the magneto-optical response from the multilayers with regard
to the polarization state of incident light. The measurements confirm a
possibility to use the multilayer structures RE/TM after calibration as
two-band magneto-optical elements for polarimetry purposes in the energy
range from approx. 700 to 1500 eV.
