ELECTRONIC CONFINEMENT BY CLUSTERS IN QUASI-CRYSTALS AND APPROXIMANTS

Quasicrystals are characterised by a long range quasiperiodic order an d the presence of many icosahedral clusters arranged in a hierarchical manner. In this paper we analyse the effect of these local environmen ts on the electronic structure by considering a model of one atomic cl uster embedded in a metallic matrix. This model leads to 'cluster boun d states', i.e. resonances of the wavefunction by clusters at differen t length scales. These states seem to be characteristic of the quasicr ystalline local order and they are very sensitive to the geometry of t he cluster. (C) 1997 Elsevier Science S.A.