Semiconducting ytterbium at high temperatures

Abstract

We report in this communication some new results on the resistivity behaviour of ytterbium in its semiconducting phase. In the high temperature region (T > 150'C) the temperature coefficient of resistance is strongly positive like that in a degenerate semiconductor. This correlates well with our earlier work on the thermoelectric behaviour of ytterbium at high pressures and high temperatures. Our measurements of the resistivity against pressure at room temperature and above show a distinct change in the slope accompanying the metal to semiconductor transition previously reported to be unobservable by other workers.