Fe57Mössbauer-effect study of preferential site occupancy in quasicrystallineAl86Cr14−xFexalloys

${}_{}{}^{57}{}_{}{}^{}\mathrm{Fe}$ Mössbauer-effect measurements are reported for rapidly quenched alloys in the series ${\mathrm{Al}}_{86}$ ${\mathrm{Cr}}_{14\mathrm{-}\mathrm{x}}$ ${\mathrm{Fe}}_{\mathrm{x}}$ (3≤x≤14). These alloys have been shown to be quasicrystalline with the icosahedral structure. Mössbauer measurements show the existence of two distinct transition-metal sites. As Fe is substituted into ${\mathrm{Al}}_{86}$ ${\mathrm{Cr}}_{14}$ in place of the Cr, the Mössbauer measurements show that the Fe preferentially occupies only one of the sites. These results are discussed in terms of structural models consisting of interconnected MacKay icosahedra.