Anisotropic Conductivity in a Decagonal Quasicrystal of Al₇₀Ni₁₅Co₁₅

Electrical and thermal transport properties of icosahedral and decagonal quasicrystals

“…7, the thermal observation window Àqf/qe at 300 K and 40 K is shown as well. The parameter x value entering the temperaturedependent chemical potential was determined from the fits as x = À0.028 meV K À2 , which is almost identical to the starting value estimated from the Mott formula of eqn (6). Using the spectral conductivity from Fig.…”

“…The anisotropy of electrical and thermal transport properties is now well established for the d-QCs [3][4][5][6][7][8][9][10][11][12] and the decagonal approximant phases, [13][14][15][16][17][18][19] where the latter are also structurally described as atomic layers stacked along the pseudo-10-fold direction, but are translationally periodic in all three dimensions. The anisotropic stacked-layer structures generally result in the anisotropy of tensorial physical properties (the magnetic susceptibility, the electrical resistivity, the thermoelectric power, the Hall coefficient and the thermal conductivity).…”

“…11,12 However, important quantitative differences were found for samples of nominally the same or slightly different chemical composition and structural quality. A striking example is the electrical resistivity, where some studies 6,7,12 report that both r 10 and r Q exhibit metallic PTC, whereas other studies [8][9][10] report that only r 10 is metallic, whereas r Q exhibits an insulator-type NTC. Single-grain samples of high structural perfection are again of essential importance to determine the true intrinsic properties of the i-QC and d-QC phases.…”

Single crystal growth of Al-based intermetallic phases being approximants to quasicrystals

“…A consequence of this structural anisotropy is strongly anisotropic physical properties, e.g. electrical [2][3][4] and thermal properties [5,6] and anisotropic friction at the surface [7] when measured along different crystallographic directions. Even in single crystal growth studies on decagonal AlCoNi quasicrystals (d-AlCoNi), a striking anisotropy in growth kinetics has been found [8] with much higher growth rates along the periodic [0 0 0 0 1] axis compared to those in quasiperiodic directions.…”

Anisotropic electrical, magnetic and thermal transport properties of the Al80Cr15Fe5decagonal approximant

“…Literature reports reveal that d-QCs exhibit anisotropy in their electronic and thermal transport properties (electrical resistivity [1][2][3], thermoelectric power S [4], Hall coefficient H R [5,6], thermal conductivity [7,8] and optical conductivity ( ) [9]), when measured along the Q and P directions. The degree of anisotropy is related to the structural details of a particular decagonal phase, depending on the number of quasiperiodic layers in one periodic unit [10,11] .…”