2. June 19 10:00

3. Together with Van der Waals Zeeman Institute Mark de Vries Olivier Toulemonde Jorge Miguel Huib Luigjes Jeroen Goedkoop Friso van der Veen Michel Zwanenburg Jeroen Bongaerts Ekkes Brück ID08/ID12B Nick Brookes Sarnjeet Dhesi Kenneth Larsson TROIKA Carsten Detlefs Gerhard Gruebel

4. Motivation Magnetism of confined systems: Thin films, surfaces, wires, clusters What happens when dimensions approach fundamental length scales Fundamental discoveries foster technological progress and vice versa Soft X-rays as a magneto-optical probe 1 nm wavelength Element specifity Submonolayer sensitivity X-ray Resonant Magnetic Scattering (XRMS)

5. Kerr Microscopy

6. This talk….. Stripe domains, domain walls and closure domains X-ray magneto-optics: absorption and dispersion Magnetic diffraction: polarization and energy dependence Evolution of stripes over the in-plane magnetization loop

7. Shape anisotropy Uniaxial anisotropy Strong stripes Stripe domains Closure domains z y x Weak stripes

8. Stripe domains in a 40 nm GdFe 5 thin film After 1 Tesla 5  m As grown

9. This talk….. Stripe domains, domain walls and closure domains X-ray magneto-optics: absorption and dispersion Magnetic diffraction: polarization and energy dependence Evolution of stripes over the in-plane magnetization loop

10. X-ray Magnetic Resonant Scattering At absorption resonance: polarisation-dependent magnetic contributions  e e’ M How to find F 0, F 1, F 2 ? ~ number of electrons/ato m Spectroscopy !

11. X-ray absorption spectra Gd M 45 (3d  4f) XAS =Im(F (o) ) XMCD=XAS(+)-XAS(-) = Im(F (1) ) XMLD=XAS(//)-XAS(  ) = Im(F (2) ) MyMy MxMx +M z -M z ê ê ê’

12. Resonance atomic scattering amplitude: real part: Kramers-Kronig Gd M 4,5 From absorption cross section to scattering cross section imaginary part: absorption

13. This talk….. Stripe domains, domain walls and closure domains X-ray magneto-optics: absorption and dispersion Magnetic diffraction: polarization and energy dependence Evolution of stripes over the in-plane magnetization loop

14. ESRF European Synchrotron Radiation Facility

15. Experimental setup

16. Diffraction patterns of disordered and aligned stripes 100  m beam Gd M 5 edge 0 1 2 -3 -2 -1 0 1 2 3

17. Scattered/Transmitted intensity Is/It=|F (1) | 2

18. y x k Aligned stripe domains k

19. Energy dependence of diffraction orders Odd orders follow F 1 (  ) Even orders follow F 2 (  )

20. Aligned stripe domains eyey exex B=0 MzMz MyMy MxMx F (1) Mz F (2) My 2 F (2) Mx 2

21. This talk….. Stripe domains, domain walls and closure domains X-ray magneto-optics: absorption and dispersion Magnetic diffraction: polarization and energy dependence Evolution of stripes over the in-plane magnetization loop

22. Magnetic diffraction in applied fields kerr loop B

23. 290 K 20 K B

24. Period Intensity Peakwidth/position Angular HWHM Mx^2

25. Intensities vs. field 1 2 3 5 4 6 x-polarization (domain walls) y-polarization (closure domains)

26. A BC D F

27. Determination resonant scattering amplitude Polarization: 3D-magnetometry Resonant Magnetic Diffraction Evolution of stripes over in- plane magnetization curve

28. Visible, UV and X-ray Absorption

30. amorphous-Gd x Fe 1-x Ferrimagnet perpendicular anisotropy Tuneable domain structure: –Thickness –Composition MBE grown Substrate: –150 nm Si 3 N 4 membrane - transmission –Si wafer - reflection MFM: disordered stripes MOKE: typical stripe loop RBS, XRD, SQUID Si 0.3 mm Si 3 N 4 150 nm a-GdFe 50 nm Al 0.2 nm After 1 Tesla

31. Kramers Kronig Scattering lengths:

32. Resonant soft x-ray scattering studies of the nanostructure of stripe domains Groupmeeting condensed matter Joost Peters June 19 10:00 !

33. Plaatje stripes uit proeschrift Bij vertellen dat we gaan laten zien dat we de scattering contributies kunnen scheiden Nucleatie??

34. Grating monochromator beamline ID08 Dragon @ESRF