FMR IN NANOSYSTEMS — DISCONTINUOUS MULTILAYERS Fe/SiO2/Fe

We present the study on the interlayer and intergranular exchange and dipolar coupling in [Fe97Si3/SiO2]5 discontinuous multilayers by means of ferromagnetic resonance. Due to strong ferromagnetic exchange coupling (J~-3 erg/cm2) the precessional motions of magnetic moments of granules are coupled and results in an acoustic and optical mode. Moreover there is notable line splitting in optical mode under external field normal to the layer, which is explained by an interlayer dipolar coupling, only possible for discontinuous layer. Some aspects of the damping processes in discontinuous multilayers are discussed as well.