Magnetic field dependences of galvanomagnetic properties of polycrystalline Bi–Sb solid solutions

The dependences of the Hall coefficient R H and magnetoresistance Δ ρ / ρ on magnetic field ( B = 0.01–1.0 T) for polycrystalline Bi–Sb solid solutions with various Sb concentrations (0–15 at% Sb) were obtained at 77 K and 300 K. On the basis of the R H ( B ) and Δ ρ / ρ ( B ) dependences, the values of magnetic field B c corresponding to the boundary of the region characterized by a constancy of R H and a quadratic dependence of Δ ρ / ρ ( B ), i.e. satisfying the criterion of weak magnetic field behavior, were determined. It was established that a decrease in temperature leads to a shift of the critical values B c to smaller magnetic fields. It was shown that the dependence of B c on composition of Bi–Sb solid solutions exhibits a non‐monotonic behavior: in the vicinity of ∼3 at% Sb and ∼8 at% Sb, where distinct minima are observed. The appearance of the minima was attributed to a sharp increase in the charge carrier mobility at the mentioned Sb concentrations due to the transition to a gapless state accompanied by the band inversion, and to the semimetal–semiconductor transition, respectively. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)