Thermal conductivity and thermoelectric power of Yb-Au system

We have measured the thermal conductivity and thermoelectric power of YbAu2 and YbAu3. Both compounds are characterized as an antiferromagnetic Kondo lattice compound. We found that the temperature dependence of thermal condu ctivity is well explained by assuming the Wiedemann-Franz law, This fact su ggests that electronic contribution is dominant and the same carriers are r esponsible for both thermal and electrical transport. Thermoelectric power shows complicated temperature dependence with plural peak structures and si gn reversal at low temperature. This behavior is characteristic of Kondo la ttice system and is explained by the competition between Kondo effect and a ntiferromagnetic interaction. (C) 1999 Elsevier Science B.V. All rights res erved.