Thermoelectric power and electrical conductivity of amorphous AuxSb100-x films near the metal-insulator transition

The thermoelectric power S and the electrical conductivity sigma of amorphous AuxSb100-x films have been investigated in the temperature range between about 5 K and 350 K. A detailed experimental investigation is performed near the metal-insulator transition occurring at x(c) = 8.1 at. % Au. For x(c) < x < 16.8 at. % the extrapolated values of sigma(0) show a scaling behaviour with a critical exponent upsilon similar or equal to 1. In the same concentration range the low-temperature slope of the diffusion thermopower S-D, i.e. S-D(T)/T\(T-->0), increases very rapidly for samples approaching x(c). A linear correlation between S-D(T)/T\(T-->0) and 1/sigma(0) is found which is interpreted in terms of a non-interacting electron system showing an Anderson transition.