Abstract
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)