Thermoelectric Power of Dilute Indium-Lead and Indium-Thallium Alloys

An earlier investigation of the thermoelectric power of dilute ($\alpha$-phase) indium-lead alloys, measured relative to pure indium, indicated that there is detailed structure superimposed on the smooth trend of the data. This investigation is now extended to include some twenty-two indium-lead alloys as well as thirteen indium-thallium alloys. For the indium-lead alloys, the existence of structure at both 273°K and 77°K is reaffirmed. On the other hand, the thermoelectric power of the indium-thallium system is found to be an extremely smooth function of the composition in the same range of solute concentration. As a consequence, it is concluded that the observed structure in indium-lead is due exclusively to changes in electronic concentration brought about by alloying.