2004/05/31 by E. Duval, L. Saviot, A. Mermet +1
Physics and Astronomy · #cond-mat.mtrl-sci
paper · pdf · doi:10.1088/0953-8984/17/23/008
published as J. Phys.: Condens. Matter 17 (2005) 3559-3565 · 9 pages without figures
arxiv created 2005/05/30 · arxiv updated 2009/12/01
The nearly dispersionless, so-called "optical" vibrational modes observed by inelastic neutron scattering from icosahedral Al-Pd-Mn and Zn-Mg-Y quasicrystals are found to correspond well to modes of a continuum elastic sphere that has the same diameter as the corresponding icosahedral basic units of the quasicrystal. When the sphere is considered as free, most of the experimentally found modes can be accounted for, in both systems. Taking into account the mechanical connection between the clusters and the remainder of the quasicrystal allows a complete assignment of all optical modes in the case of Al-Pd-Mn. This approach provides support to the relevance of clusters in the vibrational properties of quasicrystals.