Popis: |
In the present work, p-type (Bi,Sb) 2 Te 3 alloys with excess Te addition were prepared by mechanical alloying and plasma activated sintering. A preferentially orientated microstructure with the basal planes (0 0 l ) perpendicular to the pressing direction was formed, and the orientation factors of the (0 0 l ) planes of the Bi 0.5 Sb 1.5 Te 3 and Bi 0.4 Sb 1.6 Te 3 alloys were 0.12 and 0.11, respectively. Effect of excess Te content on the thermoelectric properties of the (Bi,Sb) 2 Te 3 alloys was investigated and the figure of merit of the Bi 0.4 Sb 1.6 Te 3 alloys decreased from 5.26 × 10 −3 to 4.44 × 10 −3 K −1 with increasing the amount of excess Te to 8 wt.%, this should be ascribed to the fact that the chemical composition of the δ matrix phase displayed indifference with varying excess Te content and the presence of free Te second phase. |