Effect of γ-radiation on magneto-thermoelectric properties of the extruded samples of Bi85Sb15〈Te〉 solid solution

Abstract

Extruded samples of [Formula: see text] solid solutions doped with 0.0005 at.% Te were obtained and the electrical conductivity [Formula: see text], thermoelectric power (Seebeck) [Formula: see text], Hall [Formula: see text] and thermal conductivity [Formula: see text] coefficients were investigated in the range [Formula: see text]–300 K samples and magnetic field strength up to [Formula: see text] A/m, as annealed after extrusion, non-irradiated with gamma-quanta and the same samples irradiated with gamma quanta at different doses. It was found that at low doses (1 Mrad) of irradiation, radiation defects (RDs) appear in the samples which play the role of donor centers, as a result of which the concentration of free electrons [Formula: see text], and, consequently the electrical conductivity [Formula: see text] increases, and the Seebeck coefficient [Formula: see text] decreases. These defects, scattering the current carriers, reduce their mobility [Formula: see text]. With an increase in the radiation dose, the concentration of defects also increases and free carriers are captured at the level of the RD. In this regard, the concentration of charged carrier defects [Formula: see text] and, consequently, [Formula: see text] of the sample decrease, while the Seebeck coefficient and mobility increase. The effect of a magnetic field on the electrical and thermal parameters of extruded solid solution samples also depends on the radiation dose in the sample.