Galvanomagnetic and Thermoelectric Properties of Bismuth Films Doped with Tin

Abstract

This paper presents the experimental study of the galvanomagnetic and thermoelectric properties of thin bismuth films doped with tin. The amount of tin is 0.06 at. % with the thickness ranged within 250-800 nm, and it is deposited on mica-muscovite substrates in vacuum up to 1·10-5 mm Hg. The galvanomagnetic and thermoelectric coefficients of all presented films are measured in the temperature range of 77-300 K in a magnetic field of up to 0.65 T. It is found that the classical size effect in the films occurs due to mobility of electrons being restricted by the thickness of the film. A characteristic maximum of temperature dependence of relative transverse magnetoresistance in the temperature range of 150-200 K is observed. A change in the sign of the Seebeck coefficient at the temperature of 175 K is found. It can be explained by the temperature change ratio of the electron and hole components contributions to galvanomagnetic and thermoelectric phenomena, and the contribution of holes at the L, T points of the Brillouin zone. The positive values of differential thermoelectric power in bismuth films doped with tin can become the basis for searching for the possibility of creating a p-branch of thermoelectric energy converters in the low-temperature area. The obtained results of measurements can be used for creation of a low-dimensional bismuth-based structures with a controlled hole concentration.