Spin-Polarized and Normal Hopping Magnetoresistance in Heavily Doped Silicon

Investigation of electrical resistivity ρ and magnetoresistance in single crystalline n-type silicon heavily doped with antimony in the temperature range ΔT=5-300 K and at the magnetic inductance B up to 8 T was performed. It was established that, for the temperature range ΔT=25-300 K the conductivity is of activation type, while for ΔT=5-25 K it is of variable range hopping and is described by the Mott law. Parameters of the Mott hopping were calculated. It was shown that, to explain the experimental data, the spin polarized hopping via the occupied states has to be taken into account. The obtained parameters revealed that for the low temperature range ΔT=5-11 K the spin polarized hopping dominates, while for ΔT=11-20 K the spin polarized transport is accompanied by the wave function contraction.