Gamma-resonance study of nanopowders with different dispersion and quasicrystalline phases in the Al-Cu-Fe system

⁵⁷Fe Mössbauer spectroscopy has been used to monitor synthesis of quasicrystals in the Al-Cu-Fe system and study the influence of the size of quasicrystalline particles in powder samples of the Al_63.1Cu_25.6Fe_11.3 alloy on the properties of synthesized materials. Quasicrystalline samples of different dispersion with particle sizes from 0.3 to 15 μm have been studied in the temperature range 80–295 K. It is established that iron atoms in an Al_63.1Cu_25.6Fe_11.3 quasicrystals occupy four types of structural positions, which differ in the atomic composition of the nearest environment. The results of the analysis suggest the dependence of the hyperfine-interaction parameters on the degree of sample dispersion. The components corresponding to iron atoms in both the surface layer and bulk of microparticles are isolated in the Mössbauer spectra. No magnetic hyperfine splitting has been found in the Mössbauer spectra in the entire temperature range. This fact suggests that a localized magnetic moment is absent in iron atoms.