Magnetic freeze-out in doped semiconductors the metal non-metal transition in n-type InSb

Abstract

The magnetic-field-induced metal non-metal transition has been studied in samples of n-type InSb with an excess donor concentration larger than 10¹⁴ cm⁻³ in magnetic fields up to 200 kG and hydrostatic pressures up to 7·5 kbar.

To identify the low-temperature conduction process (between 2 and 10 K) the components of the conductivity tensor have been deduced from the transverse magnetoresistance and from the Hall effect. No evidence for the ε₂ process was obtained from a plot of log σ _xx versus 1/T, either with or without pressure. In zero magnetic field the behaviour of the samples is always metallic.

For all the samples investigated the variation of the resistivity with temperature can be well explained by the temperature dependence of the mobility only.