Accueil > Français > Événements > Séminaires > Séminaires magnétisme > Archives 2008

Time-resolved Kerr microscopy studies on patterned thin-film elements

Andreas NEUDERT - University of Exeter, UK


In this talk we will discuss time-resolved wide-field and scanning Kerr microscopy. Using wide-field Kerr microscopy we investigated magnetic domain and vortex dynamics in square and rectangular permalloy (NiFe) thin film elements. In the rectangular shaped elements a closed-flux state was formed with a cross-tie wall in the center. Exciting the magnetic state with pulsed or harmonic magnetic fields resulted in the creation of additional Bloch lines within the wall and a reduction of the cross-tie spacing.

 

The higher sensitivity of scanning Kerr microscopy was used to study the spatial character of spin-wave eigenmodes in square FeCoBSi element. First the spectra was determined by exciting the magnetisation using pulsed magnetic fields. Then we excited the magnetisation at the resonance frequency and we could image the spatial character of the eigenmode at this frequency. The results can be explained using the Damon-Eshbach model for magnetostatic spinwaves.

 

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