MODIFICATION OF THE INTERACTIONS IN A LAMELLAR PHASE BY THE PRESENCE OF NANOPARTICLES

A ferrosmectic is a swollen lamellar phase in which solid magnetic par ticles have been incorporated. We measure the elastic constants of the se phases, and compare them to conventional lyotropic smectic phases. It is shown that both the bending and the compression elastic constant s are largely enhanced by the presence of particles and that their evo lution can not be accounted for by the usual models for lamellar phase s. A phenomenological model of enhanced repulsive potential between me mbranes based on steric considerations is developed and confronted to experimental results.