Physical properties of icosahedral Al─Cr─Fe─Ge alloys

Abstract

Alloys of the form Al₆₅Cr₂₀Ge₁₅ with up to 15 at.% Fe substituted for Cr have been rapidly solidified from the melt by single-roller melt spinning and have been shown to be single-phase icosahedral quasicrystals. X-ray diffraction measurements show an increase in disorder with increasing Fe content. Thermal analysis measurements indicate structural relaxation of the quasicrystalline phase prior to crystallization. Mössbauer spectra of all alloys exhibit a broadened doublet. These spectra are analysed in terms of models involving multiple transition metal sites and distributions of transition metal environments.