Magnetoresistance Study of Bi and Bi–Sb Alloys in High Magnetic Fields. I. Enhancement of Shubnikov-de Haas Oscillation Amplitude in Bi–Sb Alloys

Shubnikov-de Haas effect was observed in Bi and Bi 100- x Sb x alloys ( x is the atomic percentage of Sb) with x =0.1, 0.5 and 1.4 in pulsed high magnetic fields up to 45 T. It was found that the relative amplitude of quantum oscillation was greatly enhanced, by doping a small amount of Sb into pure Bi. An explanation is made for the enhancement of Shubnikov-de Haas oscillation based upon the theory of the diffusion size effect, assuming that the bulk electron-hole recombination time is much smaller in Bi 100- x Sb x than in Bi.