Atomic-partial vibrational density of states of i-AlCuFe quasicrystals

Abstract.

We present new results on the separation of the atomic-partial vibrational density of states for the ternary quasicrystal i-Al₆₂Cu_25.5Fe_12.5. The decomposition into three atomic-partial functions, Al-, Cu- and Fe-g(E), has been performed self-consistently with the calculation of the multi-phonon contributions. The results show the surprising result that both Cu- and Fe-g(E) are strongly peaked. The low-energy regions of Al- and Cu-g(E) show strong deviations from Debye behaviour due to the presence of non-propagating low-energy vibrational states.