Temperature dynamics of the electronic structure in dilute Bi-Sn alloys

Abstract

We study the changes of Bi electronic structure near $T$ and $L$ points of the Brillouin zone caused by doping with Sn (concentrations $\ensuremath{\le}0.08$ at.%). Hall coefficient and magnetoresistance measurements (under magnetic field up to 8 T) enabled calculation of magnetoconductivity tensor components. The usage of quantitative mobility spectrum analysis together with the isotropic approximation for band structure allowed the estimation of Fermi level position at temperatures $10\text{--}300$ K. The results have shown that Sn doping shifts the Fermi level down on the energy scale at the $L$ point (in all temperature range) and at the $T$ point under (primarily at low temperatures), leading to the decrease of band overlap.