Transport measurements in annealed single crystal tellurium

Abstract

Single crystal samples of tellurium obtained from small diameter ingots, specially grown by the Czochralski method from a melt of the purified element, were studied by measuring the electrical conductivity (σ), Hall coefficient (RH), and transverse magnetoresistance (Δρ/ρ0). As a result of annealing and etching, the Hall mobility (RHσ) and Δρ/ρ0 were substantially increased in the samples at liquid nitrogen temperature, while RH was slightly decreased. The samples were completely intrinsic above 250 °K and at room temperature Δρ/ρ0 was strictly proportional to the square of the magnetic field. Like RH and σ at this temperature, it was also independent of sample history. Two-carrier analysis at room temperature gave electron and hole mobilities of 1890 and 790 cm2 V−1 s−1 respectively. At 77 °K, Δρ/ρ0 in the annealed and etched samples was larger than expected for a simple one-carrier model with a mixture of lattice and impurity scattering.