Galvanomagnetic Studies of Sn-Doped Bi. I. Positive Fermi Energies

Oscillatory magnetoresistance and Hall effect have been studied in single crystals of Bi doped with Sn to decrease the Fermi energy to less than 5 meV. (The energy is measured from the bottom of the conduction band at the $L$ point of the Brillouin zone.) The dependence of particular electron and hole surface cross sections on the net carrier concentration $p-n$ (determined from the strong-field Hall coefficient) and the temperature dependence of hole oscillation amplitudes were examined. The data suggest that the hole band and the electron band are nonparabolic; the minimal direct gap at the center of the hexagonal zone face is estimated to be 66±25 meV. Evidence is given for the absence of any "new" bands having a large density of states within 15 meV below the Fermi energy of pure bismuth.