Atomic dynamics of the $\alpha$-(Al, Si)CuFe alloy: A crystalline approximant of a quasicrystal $\dots$

The atomic dynamics of the Al$_{0.55}$Si$_{0.07}$Cu$_{0.255}$Fe$_{0.125}$ alloy with the structure that approximates the structure of an icosahedral quasicrystal with a similar chemical composition has been investigated using inelastic neutron scattering. The partial vibrational spectra of copper, iron, and aluminum atoms and the total spectrum of thermal vibrations of the compound have been directly reconstructed from the experimental data for the first time. A combined analysis of the results obtained and the data on the atomic dynamics of the $i$-AlCuFe icosahedral quasicrystal has been performed.