Study of the Shubnikov–de Haas effect in Bi1-XSbX semimetallic alloys

The Shubnikov–de Haas oscillations in Bi1−xSbx semimetallic alloys have been studied over the Sb concentration range 0 ≤ x ≤ 7 at.%. The measurements were carried out at helium temperatures with magnetic fields H of up to 60 kOe in the basal plane of the crystal. The oscillations were Fourier analyzed on a computer to give the dependences on the Sb concentration of the maximum (Smax) and minimum (Smin) cross sections of the electron Fermi surface and of its anisotropy in Bi1−x Sbx alloys. A frequency doubling effect (spin damping) is found; it is shown that the damping angle φd, reckoned from the binary axis in the basal plane, decreases monotonically from the value φd ≈ 2.75° for pure Bi to φd ≈ 0° for the alloy with x ≈ 7 at.% Sb. The correction term to the maximum cross section Smax of the electron Fermi surface resulting from allowance for the movement of the Fermi level in a magnetic field is calculated. The change in the anisotropy of the Fermi surface of Bi1−xSbx alloys is considered within the framework of the Abrikosov–Fal’kovskii model. The angular dependence of the spin splitting Bi1−xSbx alloys is studied.