Plasmons in icosahedral quasicrystals: An EELS investigation

We present the results of an electron energy loss spectroscopy (EELS) investigation of the icosahedral quasicrystals i-Al-Cu-Fe, i-Al-Pd-Mn and i-Al-Pd-Re. The spectra of the three systems studied are very similar. Their main contribution comes from a broad plasmon like peak, which can be interpreted as an “s-p" electron plasmon damped by “d" electron interband transitions. We show that it is similar to those found in other simple crystalline aluminum-transition metal alloys, so that no specificity related to the quasicrystalline order of the alloys dominates. Received 3 November 1998 and Received in final form 16 July 1999     

Raman study of lattice dynamics in quasicrystals

We present the first Raman investigation of icosahedral quasicrystals. Broad structured bands in the energy range up to ~500 cm^− 1 have been observed in a series of AlCuFe, AlPdMn and AlPdRe systems. Original information on the vibrational density of states g(ω) was obtained for AlPdRe; for AlCuFe and AlPdMn estimated g(ω) shows a good agreement with the previous neutron results, but demonstrates finer structure. Strong increase in the parameter of electron-vibrational coupling for the low-energy vibrations and its correlation with changes in electronic conductivity has been observed in the series from AlCuFe to AlPdRe. This suggests the increase of the degree of localization for these vibrational excitations and involved electronic states.     

Crystal Growth of Large Icosahedral Zn-Mg-Y Single Grains by a Liquid Encapsulated Top Seeded Solution Growth Method

In this paper we present our work on the single crystal growth of the icosahedral phase in the system Zn-Mg-Y. Taking into account the results of our previous systematic investigation of the phase diagram Zn-Mg-Y we have been able to grow single grains of the icosahedral phase with a diameter of nearly 1cm. We apply a Liquid Encapsulated Top Seeded Solution Growth method (LE-TSSG) in order to prevent Mg- and Zn-losses during growth.