engleski

Transport in high quality decagonal quasiperiodic monocrystals d - AlCoNi vs d - AlCoCu

Decagonal quasicrystals offer unique opportunity to investigate differences of physical properties of periodically and quasiperiodically ordered structures on the same crystal [1]. That is due to unique structure of decagonal quasicrystals that is periodic along one spatial direction and quasiperiodic (with decagonal symmetry) in plane perpendicular to the periodic direction. Detailed investigations of transport properties of high quality single crystals of d - AlCoNi and d - AlCoCu revealed that, contrary to some earlier work [2], electrical resistivity shows positive temperature coefficient (PTC) of electrical resistivity in quasiperiodic plane as well as that in periodic direction but with much higher residual resistivity [3]. Maximum in electrical resistivi ty along quasiperiodic directions indicates crossover from Boltzman like to non - Boltzman like electronic transport regime. Minimum in electrical resistivity at low temperatures is most likely due to spikiness of the density of state near Fermi energy that is positioned near very narrow local minimum. Differences in thermopower among different directions suggest strong anisotropy of quasi Fermi surface. [1] J. T. Markert et al . J. Appl. Phys., 76 (1994) 6110. [2] S. Martin et al . Phys. Rev. Lett., 67 (1991) 719. [3] M. Bobnar et al . Phys. Rev. B, 85 (2012) 024205

decagonal quasicrystals; transport properties; anisotropy

nije evidentirano