Effect of sintering in ball-milled K 2Bi 8Se 13 thermoelectric nano-composites

Abstract

K 2Bi 8Se 13 has many attractive features for thermoelectric applications. Recently, K 2Bi 8Se 13-based nanocomposite materials, consisting of nano-crystalline, micro-crystalline and amorphous phases, have been fabricated based on powder technology techniques. The Seebeck coefficient has been enhanced while the thermal conductivity has been decreased presenting, thus, interesting behavior. The behavior of the materials under heat treatment conditions is now of interest, as the application of sintering process is necessary for the development of thermoelectric modules. In this work, the crystallization of the K 2Bi 8Se 13-based nano-composites is studied using Differential Scanning Calorimetry. The results show that crystallization follows a multiple-step process with different activation energies. The thermoelectric properties are also discussed in the range that crystallization occurs. © 2012 Elsevier Inc.