Two Fe/Cu multilayer systems with ultra-thin Fe layers have been inves
tigated by X-ray diffraction, Mossbauer spectroscopy and strain modula
ted ferromagnetic resonance. Mossbauer spectra show the existence of a
lpha-Fe and gamma-Fe and also a ferromagnetic phase, which has been at
tributed to the interdifussion zone. The iron magnetic moment for the
magnetic phases lies predominantly in the film plane. The magnetostric
tion constant increases with the iron thickness.