Semimetal alloy BiSb in strong magnetic and electric fields

The magnetoresistance, Shubnikov–de Haas oscillations and de volt–ampere characteristics of the compensated semimetal alloy Bi96.6Sb3.4 are studied in magnetic fields up to 200 kOe and electric fields up to 230 V/cm for H⊥E. The linear resistance is found to decrease when the magnetic field is directed close to the trigonal axis (∠H, C3 ≤ 1°) and H > 70 kOe. This is explained by rapid increase in the carrier concentration in the ultraquantum limit for the magnetic field. The ratio of the spin splitting of hole and electron energy levels to the orbital splitting is determined for H‖C3, and the dependence of the Fermi energy and carrier concentration on magnetic field is found. It is shown that in a given magnetic field, the inflection appearing in the V–I curve as a result of the phonon generation in the bulk of the sample shifts towards higher magnetic fields as compared to bismuth, while the amplitude of the Shubnikov–de Haas type oscillations of the parameter E*k = cEk/Hs decreases. These results are attributed to a stronger attenuation (as compared to bismuth) of the elastic waves and to an overheating of the electron gas following an increase in the number density of lattice defects.

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