Electrical resistivity and thermopower of liquid Ge and Si

The electrical resistivity and thermopower S of pure liquid silicon and pure liquid germanium have been carefully measured. For silicon, a new containment material was used, namely high-density graphite. This graphite has a low thermopower ( at ) a high resistivity ( at ), and little or no reaction with Si, making it an ideal containment material. The results for each liquid show a metallic value of resistivity, a small but positive temperature coefficient of the resistivity and a small thermopower. In particular, for liquid Si, , and and, for liquid Ge, , and ; all values are for the respective melting temperatures of Si and Ge. We also report a calculation of the resistivity of each liquid, using the Ziman formalism, with a recent pseudopotential and an experimental structure factor. Both our experimental and our calculated results are compared with other work.