There is a nice preprint, Thermoelectric Power of the YbT2Zn20 (T = Fe, Ru, Os, Ir, Rh, and Co) Heavy Fermions by E. D. Mun, S. Jia, S. L. Bud’ko, and P. C. Canfield
The figure below shows the temperature dependence of the thermoelectric power for the title compounds. Note that it non-monotonic, being linear at low temperatures, reaching a maximum magnitude of order k_B/e ~ 80 microV/K at a temperature T_min.
earlier post) as shown in the Figure below.
Aside: the inset on the lower right considers the Kadowaki-Woods ratio but does not make use of recent work concerning its universality.
PRB published in 2000. The temperature scales in the middle figure are characteristic of that at which there is a crossover from a Fermi liquid at low temperature to a bad metal at higher temperatures.