Hyperfine interactions and magnetic properties of Fe/Pt multilayers

A series of Fe/Pt multilayers were studied by Mossbauer Spectroscopy, SQUID magnetometry, X-ray diffraction, EXAFS & XAS and HRTEM. The Mossbauer and SQUID results demonstrate that the magnetization is out of the film plane only for the sample with the thinnest Fe layer (of the order of an atomic layer) while it is in the film plane for the rest of the samples. The Fe hyperfine fields and the spin-wave parameter b deviate from the bulk values of a-Fe. These results are discussed on the basis of a structural model where the local structure and the number of first nearest magnetic neighbors are taken into account.