1. Obtaining soft x-ray constants across the 2p edge of Fe in thin films by resonant magnetic scattering experiments of polarized soft X-rays Fabian Walter, H.-Ch. Mertins, Andreas Gaupp, Franz Schäfers, Wolfgang Gudat

2. Synchrotron Radiation BESSY II Synchrotron radiation as a light source. Radiation is produced by electrons radiating to due centripetal acceleration when following a circular path of about 240m circumference near the speed of light (Peatman) Advantages: Strong bundled light beam Strong bundled light beam Polarization and intensity can be precisely calculated Polarization and intensity can be precisely calculated Coherence and time structure Coherence and time structure High intensity of the light beam High intensity of the light beam Continuous spectrum (Peatman) Continuous spectrum (Peatman)Undulators Tuneable and known polarisation and intensity Tuneable and known polarisation and intensity Polarisation of emitted light can thus be controlled to have circular and linear components (Weiss, Sahwney) Polarisation of emitted light can thus be controlled to have circular and linear components (Weiss, Sahwney)

3. Undulator Radiation Gap and shift Gap and shift

4. Application Using synchrotron radiation for reflection and transmission measurements Magnetooptical effects Example: Determining optical constants for magnetic materials such as Fe Optical constants are not certainly known for many materials in the VUV Optical constants are not certainly known for many materials in the VUV Needed for manufacturing of computational devices Needed for manufacturing of computational devices Knowledge of polarization of the incoming light beam enlarges possibilities Knowledge of polarization of the incoming light beam enlarges possibilities

5. Magnetooptical Kerr-Effect (MOKE) L-MOKE  22   B  T-MOKE  22 B B  P-MOKE  22

6. Magnetic Dichroism

7. BESSY Soft X-Ray Polarimeter

8. Fit curves for L-Moke

9. Magnetic Dichroism

10. Fit curves for L-Moke

11. Asymetry in L-MOKE

12. Fit curves in T-MOKE

13. Asymetry in T-MOKE

14. Results for non-magnetic terms

15. Results for magnetic terms

16. Comparison with other experiments

18. Conclusion Exploiting tuneable synchrotron radiation Obtaining optical constants for Fe New technique for obtaining optical constants in the soft x-ray regime for other materials such as Co, Ni, Gd