Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
MA: Magnetismus
MA 2: Magnetic Thin Films I
MA 2.10: Vortrag
Montag, 27. März 2006, 12:30–12:45, HSZ 03
Study of domain patterns: A discussion of coherent and incoherent averaging in PNR and MOKE. — •Katharina Theis-Bröhl1, Boris Toperverg1, Jeffrey McCord2, and Hartmut Zabel1 — 1Department of Experimental and Solid State Physics, Ruhr-University Bochum, 44780 Bochum — 2Material Research Institute, Helmholtzstr. 20, 01169 Dresden
Specular Polarized Neutron Reflectivity (PNR) provides information similar but not identical to vector-MOKE. MOKE coherently averages magnetic fluctuations over the laser spot illuminating the surface, while the coherency range of the neutron beam is determined by its collimation and monochromatization. The neutron beam is well collimated in the reflection plane (x−z), while the collimation is usually relaxed along the y−axis. Due to the strong asymmetry in the coherency properties polarized neutron reflectivity is the result of an incoherent average over the y− direction of the coherent reflection from the optical potential. The incoherent averaging over a coherent signal has a big advantage for the study of domain patterns. While coherent averaging over fluctuations from domains may lead to a vanishing signal, incoherent averaging, on the contrary, does not.
In the talk we will discuss the averaging procedure for PNR using model simulations for different domain patterns. Furthermore we will compare experimental results from PNR and vector-MOKE measurements concerning the different averaging performed on patterned magnetic structures.
We acknowledge funding by DFG, SFB 491 and BMBF 032AE8BO.