On the Anomalies in the Temperature Dependence of Conductivity in Hg1−xCdxTe

Abstract

AbstractThe temperature (1.8 K ≦ T ≦ 77 K) and magnetic field (0 ≦ H ≦ 22 kOe) dependence of the conductivity σ, longitudinal magnetoconductivity σzz, and of the Hall coefficient R for gapless Hg1−xCdxTe crystals are measured. At temperatures Tmin = 6 to 11 K there occur deep minima of conductivity σ(T). It is shown that the origin of these minima cannot be accounted for by the resonance scattering of electrons by acceptors. The minima in σ(T) arise from the decrease in electron mobility caused by the increase of the number of charged centres with increasing temperature when T < Tmin and by the increase of the concentration of electron‐hole pairs when T > > Tmin. The anomalies in the conductivity (plateau) and the Hall effect (double inversion of sign) observed in the temperature range 20 K < T < 40 K are due to the contribution of three types of carriers, viz. light conduction band electrons, heavy acceptor band electrons, and valence band holes.