Non-icosahedral ordering of transition elements in Zn–TM–Sc quasicrystals

Icosahedral quasicrystals (QC) are obtained in ternary Zn–M–Sc alloys with various kinds of third element M which may be substituted for Zn. Electronic structures of cubic approximants Zn–M–Sc with M = Fe substituted for Zn at several sites are studied theoretically. It is found that the binding energies in a range of 7–9 eV per atom are gained by substitution of Fe. However, the energy difference is not sufficiently large to conclude selectivity of atomic sites for Fe substitution. The spin-polarized calculations do not suggest any signature of strong magnetism observed in the experiment. When Fe atoms occupy a pair of the sites at a very short distance, formation of the Fe complex induces further stabilization of the system.