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 am orphous AuxSb100-x films have been investigated in the temperature ran ge 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 sigm a(0) show a scaling behaviour with a critical exponent upsilon similar or equal to 1. In the same concentration range the low-temperature sl ope 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 betwe en S-D(T)/T\(T-->0) and 1/sigma(0) is found which is interpreted in te rms of a non-interacting electron system showing an Anderson transitio n.