Solidification processing of alloys in the pseudo-binary PbTe-Sb2Te3 system

Teruyuki Ikeda, Sossina M. Haile*, Vilupanur A. Ravi, Hesham Azizgolshani, Franck Gascoin, G. Jeffrey Snyder

*Corresponding author for this work

Research output: Contribution to journalArticle

64 Scopus citations

Abstract

The effects of composition and cooling rate on the microstructures of alloys in the pseudo-binary PbTe-Sb2Te3 system were investigated as a first step towards the design of nanostructured materials with enhanced thermoelectric properties. Liquid alloys of three different compositions were cooled in three distinct ways: water quenching, air cooling and furnace cooling. The resultant structures and phases were examined by electron microscopy, electron microprobe chemical analysis and electron backscatter diffraction. The compound Pb2Sb6Te11 precipitated as a metastable phase (in conjunction with PbTe and/or Sb2Te3) under all conditions. Furthermore, whereas PbTe exhibited dendritic morphology, Sb2Te3 and Pb2Sb6Te11 crystallized as lamellar platelets with preferred (0 0 1) orientation. The range of cooling rates was from ∼1 to 26 K/s, while the characteristic microstructural feature size ranged from 10 to 35 μm for dendrites, and from 15 to 50 μm for lamella. The prospects for achieving nanoscale structure are discussed.

Original languageEnglish (US)
Pages (from-to)1227-1239
Number of pages13
JournalActa Materialia
Volume55
Issue number4
DOIs
StatePublished - Feb 1 2007

Keywords

  • Dendritic growth
  • Scanning electron microscopy
  • Solidification microstructure
  • Thermoelectric

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Ceramics and Composites
  • Polymers and Plastics
  • Metals and Alloys

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