Thermal diffusivity of quasicrystalline and related crystalline alloys

Theoretical prospective of quasicrystals as thermoelectric materials

“…8,10 Thus, for most icosahedral phases the thermal conductivity at room temperature is comparable to that of zirconia (ϳ1Ϫ2 W m Ϫ1 K Ϫ1 ). 9 This low thermal conductivity of QC's is particularly remarkable in the light of Slack's phonon-glass/electron-crystal proposal for promising TEM's, 24 and it has considerably spurred the interest on the potential application of QC's as TEM's from an experimental viewpoint. In fact, one of the main advantages of QC's over other competing TEMs is that one can try to modify both the electrical conductivity and the thermoelectric power, without losing the low thermal conductivity, by properly varying the sample stoichiometry.…”

“…In fact, a broad collection of different transport anomalies have been reported during the last decade, progressively leading to a condensed matter paradigm evolution for this new class of ordered structures. 3 Thus, anomalous behaviors in the temperature dependence of electrical conductivity, 4 Seebeck coefficient, [5][6][7] and thermal conductivity [8][9][10] strongly suggest that quasicrystalline alloys are marginally metallic and should be properly located at the border line between metals and semiconductors. 11 When considered from the perspective of current trends in the search for novel high performance thermoelectric materials ͑TEM's͒, 13 the peculiar position of these alloys is quite appealing.…”

Formation and stability of icosahedral phase in Al65Ga5Pd17Mn13alloy

“…These desirable properties reportedly include low friction, high hardness, high wear and corrosion resistance, and low surface energy [2][3][4][5][6][7][8][9]. Quasicrystals were also found to have low thermal conductivity and moderate electrical conductivity, making them suitable for use in thermoelectric devices [10][11][12]. The most promising characteristic of quasicrystals is their inherently low thermal conductivity (1-3 W/m×K), it is due to essentially infinite unit cell size and scattering on large heavy ions [13].…”

Thermal conductivity of one-dimensional Fibonacci quasicrystals

“…In the first place, the heat transport is unusually low. For example, in AlPdMn icosahedral phases the thermal conductivity at room temperature is comparable to that of zirconia (1 W m Ϫ1 K Ϫ1 ), and this value decreases to about 10 Ϫ4 W m Ϫ1 K Ϫ1 below 0.1 K. 5 In the second place, the contribution of electrons to the thermal transport is, at least, one order of magnitude lower than that due to phonons over a wide temperature range (0.1 KрT р200 K). 6 In the third place, the overall behavior of the thermal conductivity is quite sensitive to the microstructure of the sample.…”