ANALYSIS OF DODECAHEDRAL VOIDS IN SINGLE-QUASI-CRYSTALLINE AL-PD-MN BY SCANNING ELECTRON-MICROSCOPY AND AUGER-ELECTRON SPECTROSCOPY

Scanning electron microscopy and microprobe Auger electron spectroscop y were used for characterizing the morphology and the surface composit ion of voids in the bulk of icosahedral Al-Pd-Mn single-quasicrystals. The samples were prepared by in-situ cleavage fracture in the ultra-h igh vacuum. The void images could be explained on the basis of an irre gular dodecahedral shape. The void facets were parallel to five-ford q uasicrystal lattice planes. The surfaces of the voids grown under clos e-to-equilibrium conditions during the cooling of the quasicrystal wer e depleted in Mn and enriched in Pd with respect to the bulk.