Ferromagnetism of composites with two interfaces

Abstract
The composite materials with two interfaces studied here are formed out of one ferromagnetic slab sandwiched between two different semi-infinite ferromagnets. The theory is developed with the help of the Heisenberg model of simple-cubic crystals. The response function is obtained for the first time and in closed form for such a composite. Its analytic knowledge enables us to study easily all the magnetic properties of such a system. An application is given here for the localized magnons within the slab.