ELECTRONIC RELAXATION-TIME AND TRANSPORT-PROPERTIES OF QUASI-CRYSTALS

A novel model for electronic transport in quasicrystals is proposed. T he electronic relaxation time due to scattering by structural and phas e disorder and quasilattice vibrations is calculated on the assumption that a multivalley fractional Fermi surface exists in the icosahedral phases. Then some kinetic characteristics like the electrical conduct ivity and thermopower are evaluated over a wide temperature range on t he basis of the fractional Fermi surface model. The calculated transpo rt properties exhibit the main experimentally observed features of qua sicrystals, such as the low density of states at the Fermi level, the low value of the electrical conductivity at zero temperature and its s quare-root temperature dependence at low temperatures, and the large a bsolute value and strong temperature dependence of the thermopower. (C ) 1995 American Institute of Physics.