Behaviour of the conductivity in metallic 70 Ge:Ga close to the metal-insulator transition

Abstract

The electrical transport properties in sample 1 of impurity concentration n=xx of the 70Ge: Ga system are studied in the absence of a magnetic field and at low temperature in the range 0.53 to 0.017 K. It is noted that the electrical conductivity of sample 1 exhibits a metallic behavior. We found that the exponent S is equal to 0.5 (σ=σ(T=0)+mTs). This result is in agreement with the theory of weak localization (WL) at 3D and the theory of electronelectron interactions (EEI). We also found that sample 1 is located near the metal-insulator transition (MIT) of the metallic side.