Thermopower, Transport Properties of (LaxCe1-x)B6 Kondo Systems and Thermoelectric Refrigeration Utilizing CeB6 Single Crystal at Cryogenic Temperatures

The results of investigation of cooling on the basis of the Peltier effect in a single crystal of CeB6 grown by the floating zone method are presented. The temperature dependencies of thermopower S(T), resistivity (T), and thermal conductivity k(T) have been measured for various (LaXCe1-X)B6 monocrystals (x=0-0.975), and the parameter ZT=TS2/ k has been calculated in the temperature range 3.5 K-300 K. The ZT value of 0.2 at 4.5 K has been obtained for CeB6 single crystal, which allows one to expect noticeable Peltier cooling in this material at that temperature. Initial measurements of thermoelectric cooling vs. electric current value were made for CeB6 single crystal at temperatures 3.5 K, 4.5 K, 5.5 K, 9.5 K. A single-stage prototype solid-state micro-refrigerator demonstrated a temperature drop of 0.2 at temperature 4.5 K.