Temperature dependence of excess carrier density and thermopower in tin-doped bismuth. Pseudo-parabolic model

Measurements of the Hall effect and magnetoresistance of four tin-doped bismuth samples in the temperature range 4.2-300K and in magnetic fields up to 6 T have been made. The resistivity data are converted to conductivities. These are reported and used to evaluate the temperature dependence of the excess carrier density and of the thermopower. The evaluation is performed with the Fermi energy as the only adjustable parameter within the pseudo-parabolic model which the authors have previously introduced. The excess carrier density is found to decrease with temperature, and this feature is used to analyse the data in terms of an acceptor energy level. A relation valid for all samples is found between this level and the Fermi level. For the thermopower agreement is found between the calculated values and the experimental ones reported in the literature.