Thermoelectric and mechanical properties of angular extruded Bi 0.4Sb1.6Te3 compounds

Takahiro Hayashi, Masayoshi Sekine, Junya Suzuki, Yuma Horio, Hirotsugu Takizawa

Research output: Contribution to journalArticlepeer-review

23 Citations (Scopus)

Abstract

P-type Bi0.4Sb1.6Te3 thermoelectric materials were prepared by an angular extrusion technique with rapidly solidified and stacked foils in a temperature range from 643 K to 838 K. Textures of the angular-extruded specimens were observed by Orientation Imaging Microscopy (OIM). The average grain size was monotonously enlarged from 4.7 to 16.1 μm while increasing the extrusion temperature. The texture of the angularextruded specimens shows that the basal planes are preferably aligned along the extrusion direction. Strong textures were observed in specimens extruded at a temperature range from 683 K to 803 K. The carrier mobility of the extruded specimens depends strongly on both the texture strength and grain size. As the extrusion temperature rises, the bending strength decreases. This change in bending strength is in good agreement with the Hall-Petch relationship. A maximum Z value of 3.33 × 10-3 K-1 and bending strength of 80.3MPa were achieved in a specimen angular-extruded at 773 K. The Z value and the bending strength were sufficiently high compared with conventional hot-extruded or hot-pressed specimens. These results indicate that the angular extrusion technique is effective in improving the thermoelectric and mechanical properties of bismuth-telluride based thermoelectric materials.

Original languageEnglish
Pages (from-to)2724-2728
Number of pages5
JournalMaterials Transactions
Volume48
Issue number10
DOIs
Publication statusPublished - 2007 Oct

Keywords

  • Angular extrusion
  • Bismuth-telluride
  • Mechanical properties
  • Rapid solidification
  • Texture
  • Thermoelectric properties

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

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