Preparation of A Thermoelectric Composite of AgSbTe₂/Ag₂Te by Mechanical Alloying

Abstract

Synthesis of AgSbTe₂/Ag₂Te composite by mechanical alloying from elemental powders is described. Mechanical alloying was done by vibratory ball milling with a ball-to-powder ratio of 100:1. The studied composition range was Sb₂Te₃-xmol%Ag₂Te (x=43-70); the (β+Ag₂Te) region in the Sb₂Te₃-Ag₂Te phase diagram. XRD analysis showed that after sufficient milling β compound AgSbTe₂ was found to be formed for x=43. The composites of various compositions were formed depending on the initial mixing ratios. The sintered compacts of the mechanically alloyed powders had homogeneous composite microstructures and exhibited the increase in the connectivity of the second phase Ag₂Te in the AgSbTe₂ matrix with increase in the Ag₂Te content.