CC BY 4.0 UnportedWeder, D.von Korff Schmising, C.Günther, C.M.Schneider, M.Engel, D.Hessing, P.Strüber, C.Weigand, M.Vodungbo, B.Jal, E.Liu, X.Merhe, A.Pedersoli, E.Capotondi, F.Lüning, J.Pfau, B.Eisebitt, S.2022-08-152022-08-152020https://oa.tib.eu/renate/handle/123456789/10016http://dx.doi.org/10.34657/9054Laser-driven non-local electron dynamics in ultrathin magnetic samples on a sub-10 nm length scale is a key process in ultrafast magnetism. However, the experimental access has been challenging due to the nanoscopic and femtosecond nature of such transport processes. Here, we present a scattering-based experiment relying on a laser-induced electro- and magneto-optical grating in a Co/Pd ferromagnetic multilayer as a new technique to investigate non-local magnetization dynamics on nanometer length and femtosecond timescales. We induce a spatially modulated excitation pattern using tailored Al near-field masks with varying periodicities on a nanometer length scale and measure the first four diffraction orders in an x-ray scattering experiment with magnetic circular dichroism contrast at the free-electron laser facility FERMI, Trieste. The design of the periodic excitation mask leads to a strongly enhanced and characteristic transient scattering response allowing for sub-wavelength in-plane sensitivity for magnetic structures. In conjunction with scattering simulations, the experiment allows us to infer that a potential ultrafast lateral expansion of the initially excited regions of the magnetic film mediated by hot-electron transport and spin transport remains confined to below three nanometers.enghttps://creativecommons.org/licenses/by/4.0/530500DichroismDiffraction gratingsElectron transport propertiesFree electron lasersLaser excitationArticle