Servizio Comunitario di Informazione in materia di Ricerca e Sviluppo - CORDIS

Thermoelectric properties of n- and p-type Ba(8)Ga(16)Ge(30)clathrates

Two crystals of clathrate Ba(8)Ga(16)Ge(30) have been grown by CTH, cut to discs and sent to DLR for investigation of their thermoelectric properties. Both crystals are of different conduction type, thus n- and p-type legs for a module could be produced from the same material, probably having their optimal performance at the same application temperature, estimated to be near 900°C.

The n-type crystal discs have been investigated with respect to the temperature dependence of electrical and thermal conductivity as well as Seebeck coefficient. From these measurements a maximum ZT of 1.1 at 800°C was calculated. The received p-type disc was characterized with respect to its homogeneity and its room temperature Seebeck coefficient by the Seebeck microprobe. Subsequently the crystal material was ground and hot pressed to obtain pellets more suitable for thermoelectric evaluation. Because of unknown optimum pressing conditions, several attempts had to be done to find a proper set of temperature, pressure and duration, with no positive final result, so far.

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Reported by

Chalmers University of Technology
Kemivägen 10
412 96 Göteborg
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