Research Article
The Anisotropic High Thermoelectric Performance in (BixSb1-x)2Te3
Abstract
The anisotropy of thermoelectric properties for (BixSb1-x)2Te3 (0.16 ≤ x ≤ 0.24) are investigated in the temperature range of 300K to 523K. Anisotropy ratiosof the specimens are around 0.72-0.93 and 1.0-1.26 for the resistivity and the thermal conductivity, respectively. In addition, a relation of k ⊥ ≈ k // /( 1−f ) is found to hold, suggesting the validity of the rule of mixture for its k and f. The maximum ZT=1.37 (at 416K) are achieved for (Bi0.16Sb0.84)2Te3. Besides, (BixSb1-x)2Te3 sample shows good mechanical properties. The compression strength for (Bi0.16Sb0.84)2Te3 is 60MPa and 65MPa in the two measured directions, which is 6 folds and 1.6 times as larger as that of commercial ingot parallel and normal to the solidification direction, respectively.