Composition controlled synthesis of Bi rich Bi1-xSbx alloy nanocrystals by a low temperature polyol process

Bi1-xSbx nanocrystals were prepared by a low temperature polyol synthesis process using PVP as a complexing agent as well as a capping agent in controlling crystal growth. This method allows for the preparation of phase pure, highly crystalline nanocrystals of 30-40 nm in diameter in large yield. The structural properties of the nanocrystals were investigated by X-ray diffraction and electron microscopy. Differential thermal analysis of the Bi1-xSbx compositions revealed a single endothermic peak at a lower melting point than that of the bulk. A formation mechanism for the Bi1-xSbx alloy nanocrystals is proposed. The results are discussed in terms of understanding the structural properties of these nanocrystals and introducing a new approach for the bottom-up synthesis of these thermoelectric materials with nano-scale domains.