Thermoelectric performance of ternary Bi–Sb–Ag alloys prepared by mechanical alloying and subsequent pressureless sintering

The alloys with the general formula of Bi85Sb15−xAgx (x=0, 1, 3, 5, 7) were prepared by mechanical alloying and subsequent pressureless sintering (Bi85Sb15 alloy was used for comparison). Their transport properties involving electrical conductivity, Seebeck coefficient, and thermal conductivity had been investigated in the temperature range of 80–300 K. The maximum absolute value of Seebeck coefficient (120 μV/K) was found at 160 K in the alloy Bi85Sb15−xAgx (x=3). The figure-of-merit of alloy Bi85Sb15−xAgx (x=1) reached a maximum value of 2.16×10−3 K−1 at 219 K, which is as large again as that of the reference sample Bi85Sb15.