Localization length and impurity dielectric susceptibility in the critical regime of the metal-insulator transition in homogeneously doped p-type Ge

We have determined the localization length (Formula presented) and the impurity dielectric susceptibility (Formula presented) as a function of Ga acceptor concentrations (N) in nominally uncompensated (Formula presented) just below the critical concentration (Formula presented) for the metal-insulator transition. Both (Formula presented) and (Formula presented) diverge at (Formula presented) according to the functions (Formula presented) and (Formula presented) respectively, with (Formula presented) and (Formula presented) for (Formula presented) Outside of this region (Formula presented) the values of the exponents drop to (Formula presented) and (Formula presented) The effect of the small amount of compensating dopants that are present in our nominally uncompensated samples, may be responsible for the change of the critical exponents at (Formula presented).