Control of grain size and crystal orientation for Bi-Sb-Te compounds

Author

Kohri, Hitoshi ; Dauphin, Xavier ; Hasezaki, Kazuhiro ; Nishida, Isao A. ; Shiota, Ichiro

Author_Institution

Dept. of Mater. Sci. & Technol., Kogakuin Univ., Tokyo, Japan

fYear

2001

fDate

2001

Firstpage

121

Lastpage

124

Abstract

Reducing the grain size of Bi_0.5Sb_1.5Te₃ was attempted by mechanical alloying under ultra low oxygen atmosphere. The powder prepared by mechanical alloying was sintered by hot pressing at 650 K under an atmosphere of 4% H₂ with Ar balance (0.1 MPa). The crystal orientation in the sintered block was random. Then the block was deformed by ultra high pressure hot pressing at 650 K or 700 K or 750 K to obtain a desirable orientation for thermoelectric properties. Improvement of the crystal orientation in the deformed specimens was not confirmed by TEM. The results of electrical resistivity and Hall coefficient measurements, however, revealed that better orientation was indicated in the electrical properties

Keywords

Hall effect; antimony compounds; bismuth compounds; crystal orientation; electrical resistivity; grain size; hot pressing; mechanical alloying; semiconductor growth; semiconductor materials; sintering; thermoelectricity; transmission electron microscopy; 0.1 MPa; 650 K; 700 K; 750 K; Ar-H₂; Ar-H₂ atmosphere; Bi-Sb-Te compounds; Bi_0.5Sb_1.5Te₃; Hall coefficient; TEM; crystal orientation; deformation; electrical properties; electrical resistivity; grain size; hot pressing; mechanical alloying; powder; sintering; thermoelectric properties; ultra high pressure hot pressing; ultra low oxygen atmosphere; Alloying; Argon; Atmosphere; Bismuth; Grain size; Powders; Pressing; Size control; Tellurium; Thermoelectricity;

fLanguage

English

Publisher

ieee

Conference_Titel

Thermoelectrics, 2001. Proceedings ICT 2001. XX International Conference on

Conference_Location

Beijing

ISSN

1094-2734

Print_ISBN

0-7803-7205-0

Type

conf

DOI

10.1109/ICT.2001.979837

Filename

979837