Properties of rare-earth-transition-metal sandwich films

In sandwich systems made by stacking coupled layers with typical thicknesses 100 nm, a specific type of domain wall may be found. This extends over the whole film surface and is termed the extended domain wall (EDW). As a result, peculiar magnetisation processes are observed, some typical examples of which are described in this paper. The formation of EDWs occurs by nucleation/propagation. Experimental evidence for the existence of EDWs is obtained from optical Kerr effect measurements. Magnetization processes are described in both analytical and numerical approaches. High susceptibility in low fields and large magnetostriction anomalies may occur in these systems.