Hall effect, thermoelectric power and electrical conductivity measurements in vitreous CdGexAs2

A series of measurements of Hall effect, thermoelectric power and electrical conductivity have been performed on the vitreous CdGexAs2 having a Ge content of 0.2, 0.3, 0.4, 0.6 and 1 mol respectively. The electrical conductivity has an exponential behaviour in the temperature range 185–500 K only for the 0.6 and 1 mol composition. It deviates from the exponential behaviour at lower temperatures for the 0.2, 0.3 and 0.4 compositions. The thermoelectric power is positive for CdGe0.2As2, negative for CdGe0.6As2 and CdGe1.0As2, whereas it changes sign for CdGe0.3As2 and CdGe0.4As2. The Hall coefficient is negative for alll compositions except for the CdGe1.0As2. The Hall mobilities differ widely for the different compositions and have the values of 1.5 × 10–2 to 1.3 × 10–1 cm2 V–1 s–1 at room temperature.