The atomic vibrational dynamics of 5 7Fe in 800-A thick amorphous (a-) 57Feo.25ScO.75, a-57Feo.67ScO.33 and a-57Feo.14Alo.86 alloy thin films has been investigated at room temperature by nuclear resonant inelastic X-ray scattering (NRIXS) of synchrotron radiation. The amorphous phase has been successfully stabilized by codeposition of Fe and Sc or Al in ultrahigh vacuum onto substrates held at -140°C during deposition. The amorphous structure of the samples was confirmed by X-ray diffraction and conversion electron Mossbauer spectroscopy. The 57Fe-projected partial vibrational density of states, geE), has been obtained from the measured NRIXS vibrational excitation probability, together with thermodynamic quantities such as the probability of recoilless absorption (f-factor), the average kinetic energy per Fe atom, the average force constant, and the vibrational entropy per Fe atom. A plot of the reduced density of states, g(E)/E 2, versus excitation energy E proves the existence of non-Debye-like vibrational modes (boson peak) with a peak energy, Ebp, in the range of 3-7 meV. Both, the boson peak height H bp and Ebp were found to depend on the composition. Above the boson peak, g(E)/E 2 exhibits an exponential decrease. Our results demonstrates that the features of the boson peak depend on the amount and type of element M (M = AI, Si, Mg, Sc).Key words amorphous alloys · Fe-Sc · Fe-AI· thin films · conversion electron Mossbauer spectroscopy (CEMS) · nuclear resonant inelastic X-ray scattering. atomic vibrational density of states · boson peak B. Sahoo (181) .