Mechanical alloying of BiSb semiconducting alloys

Polycrystalline Bi100−xSbx (x=7, 10, 12, 15, 22) semiconducting alloys were synthesized by mechanical alloying in order to achieve performant homogeneous thermoelectric materials. The influence of the milling parameters on the final homogeneity and morphology of the powders, such as ball-to-powder weight ratios (BPR=10:1, 40:1, 92:1) and balls sizes (diameters of 30 and 20 mm), was investigated. Powder samples were characterized by X-ray diffraction, differential scanning calorimetry, scanning electron microscopy and electron microprobe analysis. The results show that the samples obtained with the 10:1 BPR and four balls of 30 mm in diameter present the best homogeneity whatever the alloy composition.