Title :
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
Abstract :
Reducing the grain size of Bi0.5Sb1.5Te3 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; Bi0.5Sb1.5Te3; 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;
Conference_Titel :
Thermoelectrics, 2001. Proceedings ICT 2001. XX International Conference on
Conference_Location :
Beijing
Print_ISBN :
0-7803-7205-0
DOI :
10.1109/ICT.2001.979837
