Magnetic anisotropy and electronic structure of iron films on W(1 1 0) by spin-polarized two-electron spectroscopy

Low-energy spin-polarized two-electron spectroscopy was applied to study the spin-dependent electronic structure of 3 ML and 50 ML epitaxial iron films grown on single crystal W(1 1 0). Such films are known to show an in-plane rotation of the easy magnetization axis between thicknesses [M. Donath, Journal of Physics: Condensed Matter 11 (48) (1999) 9421; D. Sander, Journal of Physics: Condensed Matter (20) (2004) R603, O. Fruchart, J.P. Nozieres, D. Givord, Journal of Magnetism and Magnetic Materials 207 (1999) 158, H.J. Elmers, U. Gradmann, Applied Physics A: Materials Science & Processing 51 (3) (1990) 255]. Momentum distributions of correlated electron pairs I(k1, k2) excited from the films by 25 eV primary electrons were measured for two opposite polarizations of the incident beam. Energy and momentum conservation laws in the electron scattering events allow the extraction of information on the spin-dependent Bloch spectral density function of the valence electrons in iron films. The observed difference in the electronic structure of these two films is most likely due to the different crystal structures of the films.