Vibrational Density of States of Stable and Metastable Quasicrystalline Alloys

Abstract

The generalized vibrational density of states (GVDOS) of metastable and especially stable quasicrystalline alloys as determined in neutron inelastic scattering experiments is briefly presented. It is shown that the GVDOS gives the most complete information on the atomic dynamics of quasicrystals, that it is a much smoother function than originally expected from theoretical calculations and that quasicrystalline alloys and their rational approximants can hardly be distinguished on the basis of their GVDOS because of the high similarity in their atomic short-range order. The temperature dependence of the GVDOS is very similar for a quasicrystal and its approximant and also similar compared to other alloys which expand with temperature. For decagonal quasicrystals a nearly quantitative description of the GVDOS can be obtained and even the development of the GVDOS with temperature can be accounted for very satisfactorily.