Surface decorations of Al-Cu-Fe and Al-Cu-Co single quasicrystals

We studied surface decorations of faceted icosahedral Al-Cu-Fe and decagonal Al-Cu-Co single quasicrystals by the scanning electron microscopy using primary and secondary electrons. Both types of single quasicrystals exhibited decorations on their facets, however the character of the decorations was totally different. Three kinds of decorations has been developed. On icosahedral Al₆₀Cu₂₆Fe₁₄ quasicrystals we found three kinds of decorations: cellular, cavity type and fractal-like. There was no evident difference in chemical composition between the inner dodecahedra and the decorations of all types. Surface decorations found on decagonal Al _73.5Cu_17.5Co₉ quasicrystals formed a kind of irregular dendritic stars on the separate bright islands.