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Journal of Nanomaterials
Volume 2013 (2013), Article ID 821657, 6 pages
http://dx.doi.org/10.1155/2013/821657
Research Article

Fabrication and Enhanced Thermoelectric Properties of Alumina Nanoparticle-Dispersed Bi0.5Sb1.5Te3 Matrix Composites

Powder & Ceramic Materials Division, Korea Institute of Materials Science, 797 Changwon-daero, Seongsan-gu, Changwon-si, Gyeongnam 642-831, Republic of Korea

Received 25 June 2013; Revised 14 September 2013; Accepted 14 October 2013

Academic Editor: Hyung-Ho Park

Copyright © 2013 Kyung Tae Kim and Gook Hyun Ha. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Alumina nanoparticle-dispersed bismuth-antimony-tellurium matrix (Al2O3/BST) composite powders were fabricated by using ball milling process of alumina nanoparticle about 10 nm and p-type bismuth telluride nanopowders prepared from the mechanochemical process (MCP). The fabricated Al2O3/BST composite powders were a few hundreds of nanometer in size, with a clear Bi0.5Sb1.5Te3 phase. The composite powders were consolidated into p-type bulk composite by spark plasma sintering process. High-resolution TEM images reveal that alumina nanoparticles were dispersed among the grain boundary or in the matrix grain. The sintered 0.3 vol.% Al2O3/BST composite exhibited significantly improved power factor and reduced thermal conductivity in the temperature ranging from 293 to 473 K compared to those of pure BST. From these results, the highly increased ZT value of 1.5 was obtained from 0.3 vol.% Al2O3/BST composite at 323 K.