Magnetoresistance in plastically deformed InSb crystals at 77 K

Abstract

Magnetoresistance (MR) measurements, at 77 K, on deformed and undeformed samples of n-type InSb single crystals have been performed. Positive MR was observed in all samples. MR in undeformed samples was H 2 dependent and its variation with magnetic field was found to fit with an empirical law, MR = (B 1H) 2 (1 + (B 2H) 2 ) suggested by Khosla and Fischer. For deformed samples, a similar law, with a power less than 2, was found to be suitable. The constants and the power were determined by applying the least-squares method. The power was observed to decrease quadratically with the increase in dislocation density ( m = pN 2 + qN + r). The saturation value of MR was estimated to 1. (1) occur at higher magnetic fields in samples of higher dislocations 2. (2) increase with an increase in dislocation concentration as related by the empirical law ( Δρ ρ 0) sat = CN 2 1 + DN 2 The positive MR, as a result of the magnetic field dependence of the Hall coefficient, was interpreted in terms of the magnetic freeze-out model for the charge carriers.