Shubnikov-de Haas effect and semimetal-semiconductor transition in bismuth-antimony alloys in high magnetic fields

Abstract

Shubnikov-de Haas effect is observed in Bi and BiSb alloys (containing 0.1−4.4 at.% Sb) in pulsed high magnetic fields up to 420 kG. It is found that the amplitude of the quantum oscillation remarkably increases by mixing a small amount of Sb in Bi, and that the magnitude of the Hall electric field in BiSb alloy (0.1 at.% Sb) is much larger than that in pure Bi. These observations demonstrate the difference in the scattering mechanism of carriers between Bi and BiSb alloys. The magnetic field induced semimetal to semiconductor transition is observed in BiSb alloy with 4.4 at.% Sb. From the analysis of the Shubnikov-de Haas oscillation in BiSb, the field at which the semimetal to semiconductor transition will occur in Bi is estimated as about 1 MG for the field direction parallel to the binary axis.