The Temperature Dependence of Some Electrical Properties in Dilute Bi-Sn and Bi-Te Alloys

The measurements were made on the electrical resistivity, the magneto-resistance and the Hall coefficient of the bismuth alloys containing small amounts of tin or tellurium as function of temperatures between 4.2° and 400°K. In Bi-Sn alloys a hump appeared in the resistivity, the magnetoresistance and the Hall coefficient versus temperature curves respectively, while in Bi-Te alloys it did in the magnetoresistance and the Hall coefficient versus temperature curves of only heavily-doped specimens. Such behaviors could be explained qualitatively in terms of the electronic band structure and the change of the carrier concentration. Especially, the appearance of such humps in Bi-Te alloys were explained in terms of the thermal excitation of the electrons from the Fermi level to the upper empty conduction band.