Heusler Thermoelectric Alloy Obtained by Solid State Reaction

Abstract

The thermoelectric alloy Ni51Mn19Sn30 was obtained by mechanosynthesis, from elemental powders in a planetary ball mill. The milling was carried out in the argon atmosphere for 4 h and 10 h. The structural evolution was studied by X-ray diffraction. At 4 h a mixture of phases was found. After 10 h of milling, a complete reaction led to the formation of the Heusler Ni2MnSn alloy was observed. The morphological characterization of the powder has been performed using scanning electron microscopy (SEM). The particle shape changes upon milling, leading to irregularly shaped particles of small dimensions. The particle size distribution indicates that milling leads to the fragmentation of powders.