Hopping Conductivity in Single Crystals of Eutectic Composite (InSb)98.2 - (NiSb)1.8

Abstract

The eutectic composite material (InSb)_98.2 - (NiSb)_1.8 was obtained. The material consists of a single crystal InSb semiconductor matrix and oriented NiSb needles. By X-ray diffraction, it was found that the InSb semiconductor matrix had a zinc blende structure F43m with a crystal lattice parameter equal to a = 6.49(1) Å. The NiSb needles had a hexagonal structure of the nickel arsenide type P63/mmc, the unit cell parameters of the NiSb needles were a = 3.94(1), c = 5.14(1) Å. The electrical conductivity of eutectic composite material (InSb)_98.2 - (NiSb)_1.8  was measured. The mechanisms of electrical conductivity were determined for a singlecrystal composite sample. The region of realization of the variable range hopping mechanism of Shklovsky-Efros was established in the absence of a magnetic field. The temperature of the beginning of the hopping conductivity was calculated Тν = 126.1 К. Microscopic parameters were calculated for the sample (InSb)_98.2 - (NiSb)_1.8 when the NiSb needles were oriented parallel to the direction of the magnetic field and perpendicular to the direction of the current through the sample. Was determined the width of the Coulomb gap ∆ = 6.3 meV, the dielectric permittivity к = 11, the density of the localized states g₀ = 1.66 · 10¹⁶ cm^-3 meV^-1  and the localization radius a = 245.8 Å.