A comparative study of Spark Plasma Sintering (SPS), Hot Isostatic Pressing (HIP) and microwaves sintering techniques on p-type Bi2Te3 thermoelectric properties

The sintering of a synthesized p-type Bi2Te3 nano-powder has been investigated by three different techniques. Sintering techniques such as Hot Isostatic Pressing (HIP), microwave sintering and Spark Plasma Sintering (SPS) also known as electric field-assisted sintering technique (FAST) have been compared in terms of sintering parameters i.e. temperature, pressure, and power, microstructure and thermoelectric properties of the prepared ceramics. This study demonstrates that the highest figure of merit ZT has been obtained using microwaves or SPS techniques. Ceramics observations reveal differences in microstructure as well as the presence of intra-granular precipitates in the pellets sintered by the three techniques. We finally conclude about the relationship between properties and microstructure to get optimum thermoelectric materials. (C) 2012 Elsevier Ltd. All rights reserved.