Effect of Gamma Irradiation on the Electrical Properties of Extruded Bi0.85Sb0.15 Solid Solution Samples Doped with Pb Acceptor Impurities

Abstract

The effect of gamma irradiation on the electrical properties of extruded Bi_0.85Sb_0.15 solid solution samples doped with 0.001 to 0.05 at % Pb has been studied in the range ~77–300 K. The results suggest that irradiation of the undoped material to a gamma dose of ~1 Mrad produces donor defects and leads to an increase in carrier concentration n and electrical conductivity σ. The radiation-induced donor defects in the material containing 0.001 at % Pb compensate Pb acceptor centers, reducing σ. In the materials containing ≥0.005 at % Pb, conduction electrons are compensated by Pb acceptor centers, so electrons generated by gamma irradiation lead to an increase in σ. A good correlation is observed between the dependences of electrical conductivity σ, thermoelectric power α and Hall coefficient R_H on Pb content and gamma irradiation dose.