Thermoelectric properties of hot-pressed YbAl/sub 3/ compound over temperature range 150-800 K

Small crystals of YbAl/sub 3/ have been obtained using the Bridgman or a direct synthesis method and subsequently disc-shaped compacts prepared using a hot-pressing technique. The Seebeck coefficient, electrical resistivity, thermal diffusivity and specific heat capacity were measured over a temperature range 200-800 K. Although the thermal conductivity of YbAl/sub 3/ is much higher than that of Bi/sub 2/Te/sub 3/ based alloys, YbAl/sub 3/ possesses an electrical power factor which is more than double those of Bi/sub 2/Te/sub 3/ based alloys. The thermoelectric figure of merit at room temperature is about 1.1/spl times/10/sup -3/ K/sup -1/, which is only a third of Bi/sub 2/Te/sub 3/ based thermoelectric materials. However, YbAl/sub 3/ may be a useful material for electrical power generation using waste heat with its substantially large electrical power factor providing a large electrical power density.