Electrical Conductivity and Thermoelectromotive Force of Solid Solutions of the Systems: BI2SE3 -- SB2 TE3 and BI2TE3 -- SB2SE3

摘要

On the basis of measurements of electrical conductivity and thermal E M F of solid solutions with laminar structure of the tetradymite type, it was established that in the system Bi2Se3 -- Sb2Te3 at room temperature, electrical conductivity changes on a curve with a minimum at composition of approximately 70 mole % Sb2Te3. Thermal E M F of the n-type, characteristic for Bi2Se3, with the growth of Sb2Te3 in solid solutions to approx. 50 mole % is increased from -60 to -116 micro v/deg, and at approximately 60 mole % Sb2Te3 a change is observed in the sign of conductance from minus to plus and a growth of thermal E M F to maximum + 360 micro v/deg at 70 mole % Sb2Te3. In the system Bi2Te3 -- Sb2Se3 at room temperature, electrical conductivity of an n-type solid solution based on Bi2Te3 decreases with the growth of concentration of Sb2Se3 on a smooth curve, and thermal E M F to 50 mole % Sb2Se3 is somewhat increased (from 100 to 127 micro v/ deg), and then quickly decreases to 6 micro v/deg at 70 mole % Sb2Se3. (Author)