Magnetotransport in thermoelectric materials.

The mechanisms behind the magnetic field and temperature dependent thermoelectric effects that have recently been found experimentally in the electrical resistivity, thermopower and thermal conductivity of nanocomposite samples of Bi2Te3 and related compounds is studied. Large deviations in the transport coefficients in the presence of an applied magnetic field, both when the magnetic field is parallel and perpendicular to the transport direction has been observed in Bi2Te3 compounds, despite the small electronic mean free paths in these materials. An accurate analysis of the experimentally measured data leads to the estimation of electron mean free path and extraction of lattice thermal conductivity contribution from the total thermal conductivity. We will apply a Boltzmann transport equation based formalism to analyze the experimental data and improve the accuracy of the estimation of electronic and lattice part of the thermal conductivity. A particular attention will be paid to the analysis of the anisotropic effects in these samples.