Quantum-limit anisotropic magnetoresistance of semiconducting n-BiSb alloys

The magnetic-field dependences of resistivity and Hall coefficient of single crystals Bi_0.93Sb_0.07 alloys were investigated at low temperatures. For H∥C₃ and j∥C₁ orientation the cyclotron frequencies of all three ellipsoids are equal and the electron concentration raises with the magnetic field in quantum limit. For H∥C₂ and j∥C₁ the quantum oscillations of resistivity were observed connected with the electrons of two ellipsoids, at higher fields the transition to the quantum limit takes place. The magnetic field increase in the quantum limit leads to the increase of electron energy from secondary ellipsoids and to their migration to the main ellipsoid. For H∥C₁∥j orientation the quantum oscillations of resistivity were connected with all three ellipsoids. The electron energy for main ellipsoid rises in quantum limit with magnetic field, leading to the migration of carriers from main ellipsoid to the secondary ellipsoids.