Calculation of the magnetization in an exchange coupled layer

Exchange coupled thin films of a soft magnetic film and an anti-ferromagnet are of interest as a way of providing bias for magneto-resistive recording heads. In this paper the influence of magnetic and geometrical parameters of the soft magnetic film on the magnetization curve and the permeability were derived from micromagnetic theory. A comparison with experimental data showed, that the exchange coupling at the interface of the soft magnetic layer to the antiferromagnet is very weak. It was found that the average of the exchange stiffness constant across the boundary layer appears to be only1/2000of that in the bulk of the soft magnetic layer for the system permalloy/FeMn. This suggests that the magnitude of exchange anisotropy could be considerably increased, if the interface were improved.