Magnetoresistance Study of Bi and Bi–Sb Alloys in High Magnetic Fields. II. Landau Levels and Semimetal-Semiconductor Transition

Shubnikov-de Haas effect in magnetoresistance was investigated in Bi and Bi 100- x Sb x alloys with various x ranging from 0.1 to 12.2 (atomic percent) under pulsed high magnetic fields up to 45 T. For H //binary, sharp kinks corresponding to the magnetic-field-induced semimetal to semiconductor (SM-SC) transition were observed for x =4.4 in addition to the Shubnikov-de Haas peaks of holes. In pure Bi, SM-SC transition was observed for H //binary at 88 T in the magneto-transmission of the far-infrared radiation. For x >8, on the other hand, semiconductor to semimetal (SC-SM) transition was observed for H //trigonal. In Bi and Bi 95.6 Sb 4.4 for H //binary, band parameters were determined based on the Vecchi et al .'s model, by analysing the Shubnikov-de Haas oscillation and SM-SC transition field.