Title :
Texture formation in extruded rods of (Bi,Sb)2(Te,Se)3 thermoelectric alloys
Author :
Vasilevskiy, D. ; Simard, J.-M. ; Bélanger, F. ; Bernier, F. ; Turenne, S. ; L´Ecuyer, J.
Author_Institution :
Ecole Polytech. de Montreal, Que., Canada
Abstract :
The anisotropy in both the electrical and mechanical properties of (Bi,Sb)2(Te,Se)3 thermoelectric alloys, and in turn in their overall performance, requires a close control of the alloy texture. In this work we have investigated extruded rods of n- and p- type thermoelectric alloys with square (25.4 mm ×25.4 mm) and circular (25.4 mm diameter) cross-sections. Figures of merit of up to 3.2×10-3 K-1 for p-type alloys and 2.8×10-3 K-1 for n-type alloys have been obtained for all extruded sizes. Texture investigations were made by X-ray diffraction. Electrical characterization and mechanical strength were measured in the longitudinal and radial directions. Comparison of the experimental data with numerical simulations shows that there is a correlation between the sample texture and the value of the equivalent plastic strain experienced by the material during the hot extrusion process.
Keywords :
X-ray diffraction; antimony compounds; bismuth compounds; extrusion; mechanical strength; plastic deformation; semiconductor materials; texture; thermoelectricity; (BiSb)2(TeSe)3; 25.4 mm; X-ray diffraction; figures of merit; hot extrusion; mechanical strength; n-type alloys; p-type alloys; plastic strain; texture formation; thermoelectric alloys; Bars; Conductivity; Crystalline materials; Electric resistance; Electric variables measurement; Mechanical variables measurement; Surface texture; Testing; Thermoelectricity; X-ray diffraction;
Conference_Titel :
Thermoelectrics, 2002. Proceedings ICT '02. Twenty-First International Conference on
Print_ISBN :
0-7803-7683-8
DOI :
10.1109/ICT.2002.1190257
