Giant thermoelectric power of (La, Ce) Al₂

We have measured the thermoelectric power of LaAl2 and of (La, Ce)Al2 alloys between 0.3 and 9 K. A large, negative peak caused by the Kondo effect of the Ce impurities has been observed at about 1 K. The peak value of about −16 µV/K obtained from the Nordheim-Gorter rule suggestsV=+0.05 eV andJ=−0.11 eV for the interaction energies of the potential and exchange scattering of the conduction electrons by the Ce impurities