THEORY OF THE SPIN DYNAMICS OF BULK FE AND ULTRATHIN FE(100) FILMS

We present theoretical studies of the spin dynamics of bulk Fe and of ultrathin Fe(1 0 0) films, within an empirical tight binding descripti on of the one electron energies. We use a Slater-Koster parameterizati on of the bulk paramagnetic energy bands, and apply these to the film. Ferromagnetic ground states are generated by introducing intra-atomic Coulomb repulsion within the d shell of each atom. The intra-atomic C oulomb matrix elements are expressed in terms of three Racah parameter s, whose values are chosen to describe the ferromagnetism of the bulk. We calculate the transverse dynamic spin susceptibility of both the b ulk and a film with a (1 0 0) surface, within the random phase approxi mation (RPA). Such an approach describes the spin wave excitations of these systems, and their Stoner spectrum as well. (C) 1998 Elsevier Sc ience B.V. All rights reserved.