Stoichiometry of Quasicrystalline Al-Mn

Electron microscopy has shown that in rapidly solidified Al-(14-20) at. %Mn alloys a new metastable phase of a quasicrystalline phase with the icosahedral symmetry, which was first discovered by Shechtman et al. (Phys. Rev. Lett. 53 (1984) 1951), is formed but with a considerable amount of fee Al second phase in alloys with lower Mn content. From the change with Mn content of the intensity of fee Al lines in the powder X-ray diffraction spectrum, the stoichiometry of the Al-Mn quasicrystalline phase is concluded to be nearly AUMn (~20.5 at. %Mn), being at variance with the reported composition of AleMn.