Metal-insulator Transition in \({}^{70}\)Ge: Ga Semiconductor by Applying the Scaling Laws

Abstract

In this article, we focus on the scaling theory of Abraham et al. without and with a magnetic field on the metallic side of the Metal-Insulator Transition (MIT) for the three-dimensional system 70 Ge: Ga, at very low temperatures. In particular, we have determined the zero temperature conductivity critical exponent when the MIT transition occurs with the variation of the impurity concentration (υ = 0.503) and with the application of a magnetic field (υ = 1.06). We have also estimated the critical magnetic field B C that separates the metallic behavior (B < B C ) from the variable-range hopping regime (B > B C ). The data are for a 70 Ge: Ga sample prepared and reported by Itoh et al.,