Stable quasicrystals exhibit specific and unusual physical properties,such as,diamagnetism,low electricla conductiviyt,low thermal conductiviyt,and large themoelectric power at room temeprature.these properties can be understood with a Bragg's reflexions scheme due to their dense filled reciprocal space.this leads to small gaps on the Fermi surface (some tenths of eV),much narrower than the usual Hume-rothery ones (of order of 0.5 eV) which explain their stability.these gaps lead to the existence of quasi Umklapp processes,crucial for the interpretation of thermoelectirc powerIn some cases,the positive phonon drag contribution due to Umklapp processes,add with the electronic one's and dominates at room temperature with a large positive thermoelectric power.A crude estimate of the figure of merit gives some hope for applciations of some quasicrystals and high approximants as new thermoelectric materials.
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