Naslov
Thermoelctric properties of quasicrystals

Autori
Popčević, Petar ; Velebit, Kristijan ; Stanić, Denis ; Ivkov, Jovica ; Bihar, Željko ; Bilušić, Ante ; Smontara, Ana

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
14th Joint Vacuum Conference - 12th European Vacuum Conference - 11th Annual Meeting of the German Vacuum Society - 19th Croatian - Slovenian Vacuum Meeting / - , 2012

Skup
14th Joint Vacuum Conference - 12th European Vacuum Conference - 11th Annual Meeting of the German Vacuum Society - 19th Croatian - Slovenian Vacuum Meeting

Mjesto i datum
Dubrovnik, Hrvatska, 04.06.2012. - 08.06.2012

Vrsta sudjelovanja
Pozvano predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
Quasicrystals; charge and heat transport; thermoelectric figure of merit

Sažetak
Quasicrystals are materials that fascinate scientists for more than thirty years: discovery of such materials that possess long-range translational and non-crystalographic orientational order eventually led to re-definition of the term ‘crystal’. The peculiar structure is not the only physical property that makes quasicrystals so interesting: from the point of view of transport, they closely match the concept that a good thermoelectric should have: a glasslike material in relation to phonon, and a metal in relation to electronic transport. Generally, quasicrystals are intrinsically poor thermal conductors – the lack of long-range periodicity disturbs phonon- (and consequently the heat-) flow considerably. Contrary, the charge transport is tunable by difference in compositional, impurity and sample-preparation properties, giving the opportunity to optimize their thermoelectric figure of merit. In this work we discuss charge and heat transport properties of aluminum-based quasicrystals and compare them with related materials being quasiperiodic at short- and periodic at long-range scale, known as quasicrystal approximants. The charge transport (electrical conductivity and thermoelectric power) is analyzed within the spectral conductivity model. The measured thermal conductivity data are analyzed and discussed by the model that takes into account modification of the Wiedemann-Franz law typical for the quasicrystalline structure, and contributions of both extended and localized lattice vibrations. However, the current data tend to indicate that they are not suitable candidates for a new, high-performance thermoelectrics since the considerable increase of the thermoelectric power seems not to be likely.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

Napomena
The paper was presented as an invited talk by Ante Bilušić. This work was done within the activities of the European Integrated Center for the Development of New Metallic Alloys and Compounds - C-MAC.

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