In this paper we report a study of the magnetostatic coupling of square dot
films and strips of films of Permalloy/Copper/Permalloy (200/20/200 nm).
Results show a good magnetostatic coupling which leads to a monodomain
structure in the case of square dots as it is observed from hysteresis
loops. These monodomain structures appear to be stable for a wider range of
dot dimensions rather than in monolayers. Magnetic simulations also support
the existence of these kind of magnetic structures. Results obtained for
strips are also reported. These samples exhibit a multidomain structure
where it is possible to observe a coupling between domains and also between
domain walls in the different magnetic layers.