Electron transport properties of amorphous Mg-Zn alloys with different Zn compositions

The electrical resistivity, Hall coefficient and thermoelectric power have been measured over a wide temperature range for six amorphous Mg-Zn alloys with compositions between 22.5 and 35 at.% Zn. The electrical resistivity shows a very shallow minimum at about 10K and then increases as T 2 up to about 30K. A small and broad maximum is observed at a temperature T max ranging from 30 to 50K. Subsequently, the resistivity decreases as -(T-T max ) 3 2/. This newly found temperature dependence continues up to a temperature T 2 , above which more or less linear temperature dependence is seen with negative TCR. All the features described above are composition dependent. The Hall coefficient is negative and temperature independent. The data are employed to determine the critical parameters 2k F /K p . The value of TCR is found to be always negative, while the ratio 2k F /K p is situated around 1.1. The thermoelectric power is negative and shows a non-linear behaviour with temperature below about 200K.