Spin dynamics and spin-polarized EELS spectra of model itinerant-electron magnetic films

The spin excitations of model itinerant-electron ferromagnetic and antiferromagnetic ultrathin films are studied theoretically. The discussion is based on the one-band Hubbard model, treated in mean-field theory. A description of the spin excitations is generated by means of the random-phase approximation. We find both the low-lying collective modes (spin waves) and the spectrum of Stoner excitations. We also compute the spin-polarized electron-energy-loss scattering (SPEELS) spectra for our model films. The applications of SPEELS to the study of magnetic excitations at surfaces is discussed.