EXAFS study of the Fe local environment in icosahedral AlCuFe and its relation to magnetism of quasicrystals

An extended X-ray absorption fine structure study of the transition metal sites in an icosahedral Al 63Cu 25Fe 12 quasicrystal was performed. The nearest-neighbor coordination shell of the Fe atoms was found to contain Al atoms only, whereas the Cu atoms are surrounded predominantly by the Al atoms and some Cu atoms as the nearest neighbors, but no Fe atoms. The results give experimental support to the physical picture of Fe atoms embedded in an Al-rich environment without direct contacts to other Fe's, providing a basis for the study of unusual magnetism in transition-metal-containing aluminum-based quasicrystals.