Galvanomagnetic Properties of n-Type InSb at Low Temperatures II. Magnetic Field-Induced Metal-Nonmetal Transition

Experimental evidence for the magnetic field-induced metal-nonmetal transition in n–InSb has been obtained, under the magnetic fields up to 13.3 kOe, by systematically investigating the Hall coefficient and the transverse magnetoresistivity for the samples containing 2×10 14 –4×10 15 cm -3 of donors with nearly fixed compensation ratio K ∼0.5 at liquid helium temperatures. The donor concentration dependence of the critical magnetic field strength at the transition satisfactorily agrees with the theoretical prediction on the impurity band. The observed minimum metallic conductivity proves practically insensitive to magnetic field and increases with increasing density of localized centers, in accord with Mott's concept of the metal-nonmetal transition in doped semiconductors.