Cd hyperfine fields at the bcc Fe Õ Co interface

We present ab initio calculations for the magnetic properties of the ~001! and ~110! bcc Fe/Co interfaces. The calculations are performed by the Korringa-Kohn-Rostoker Green’s-function method using the local-density approximation of density-functional theory. Of central interest is the relation between the hyperfine fields induced on substitutional Cd probe atoms and the magnetization profile at the interface. We compare the calculated Cd hyperfine fields with the ones measured by a time-differential perturbed angular correlation spectroscopic experiment @B. Swinnen, J. Meersschaut, J. Dekoster, G. Langouche, S. Cottenier, S. Demuynck, and M. Rots, Phys. Rev. Lett. 78, 362 ~1997!#. The comparison suggests that the considered interfaces between Fe and Co are strongly interdiffused, so that no ‘‘simplified’’ relation exists between the measured hyperfine fields and the magnetic moments at the interface.