In this thesis I present the results I obtained on the magnetic properties and magnetisation dynamics of magnetic thin films coupled across a non ferromagnetic or an antiferromagnetic layer. We used X-ray absorption spectroscopy (XMCD) as well as Kerr effect and Kerr microscopy in pump-probe mode. The time-resolved XMCD measurements exploit the time-structure of synchrotron radiation to get access to magnetisation dynamics with element selectivity. A recent extension of this technique is time-resolved PEEM microscopy. These techniques have been used to study magnetisation dynamics in spin valve systems where the magnetostatic coupling influences the reversal mode. In Pt/Co multilayers coupled with an AF layer the magnetic domain structure is strongly influenced by the F/AF interaction.
