Contribution of magnons to the properties of [Co/Ag] super lattice

Abstract

In this work we study the elementary excitations and the magnetic properties of super lattice [Co/Ag]. The study is obtained in framework of the Heisenberg model for a ferromagnetic system made of N atomic planes. The exchange and the dipolar interactions, the magneto-crystalline anisotropy and surface anisotropy are all taking in account. In the presence of the exchange alone, the analytical expressions of the excitation spectrum  and the magnetization per spin =  are obtained using the Green function formalism. The values of the exchange integrals deduced from the comparison of  with experimental measurements are in good agreement with results of previous studies for analogous magnetic super lattices. A numerical study of the combined effect of dipolar interactions and surface anisotropy is also reported.