engleski

Quasicrystals: Potential Thermoelectric Materials

The problem of designing of more efficient thermoelectric devices has been and remains to be an important and vital problem of physics and technology. Its solution depends directly upon the process of obtaining more efficient thermoelectric materials. Such materials must possess high values of electrical conductivity and Seebeck coefficient as well as the lowest possible values of thermal conductivity. These requirements are in general of a contradictory character. Most quasicrystals exhibit very low thermal conductivity values (1 5 W/Km) with the signature plateau region around 50 150 K, which is typical of many amorphous materials. However, in the plateau region the thermal conductivity of quasicrystals can be almost an order of magnitude higher than the thermal conductivity of many amorphous solids. Even with the low thermal conductivity, quasicrystals have a relatively broad range of electrical conductivity [i.e., 0.01 5000 (Ohmcm)-1]. An advantage of quasicrystals is that the value of electrical conductivity as well as of the thermoelectric power can be modified by varying the composition without sacrificing the low thermal conductivity exhibited in these materials. For these reasons, we have done a systematic investigation of the electrical and thermal transport properties of different quasicrystalline materials, which up to now have not been the subject to investigations for thermoelectric applications. In this paper we focus on the interesting electrical and thermal transport properties of single phase icosahedral Al-Pd Mn.

termoelectric materials; quasicrystals; figure of merit; electrical conductivity; Seebeck coefficient; thermal conductivity

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