TY - GEN
T1 - Control of crystallographic orientation and grain refinement in Bi 2Te3-based thermoelectric semiconductors by applying high pressure torsion
AU - Ashida, Maki
AU - Hamachiyo, Takashi
AU - Hasezaki, Kazuhiro
AU - Matsunoshita, Hirotaka
AU - Kai, Masaaki
AU - Horita, Zenji
PY - 2008
Y1 - 2008
N2 - Prepared were p-type Bi2Te3-based thermoelectric semiconductors, having a grain-refined microstructure and a preferred orientation of anisotropic crystallographic structure. Disks with a nominal composition Bi0.5Sb1.5Te3.0 were cut from an ingot grown by the vertical Bridgman method (VBM) and deformed at 473 K under a pressure of 6.0 GPa by high pressure torsion (HPT). The crystal orientation was characterized with X-ray diffraction. The microstructures were characterized by using optical microscopy and scanning electron microscopy. It was found that the HPT disks had a fine and preferentially oriented grain compared to that of the VBM disks. Further, the power factor of the HPT disks was about twice as large as that of the VBM disks. These results indicate that HPT is effective for improving the thermoelectric properties of Bi2Te3-based thermoelectric semiconductors.
AB - Prepared were p-type Bi2Te3-based thermoelectric semiconductors, having a grain-refined microstructure and a preferred orientation of anisotropic crystallographic structure. Disks with a nominal composition Bi0.5Sb1.5Te3.0 were cut from an ingot grown by the vertical Bridgman method (VBM) and deformed at 473 K under a pressure of 6.0 GPa by high pressure torsion (HPT). The crystal orientation was characterized with X-ray diffraction. The microstructures were characterized by using optical microscopy and scanning electron microscopy. It was found that the HPT disks had a fine and preferentially oriented grain compared to that of the VBM disks. Further, the power factor of the HPT disks was about twice as large as that of the VBM disks. These results indicate that HPT is effective for improving the thermoelectric properties of Bi2Te3-based thermoelectric semiconductors.
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U2 - 10.4028/www.scientific.net/msf.584-586.1006
DO - 10.4028/www.scientific.net/msf.584-586.1006
M3 - Conference contribution
AN - SCOPUS:56349140272
T3 - Materials Science Forum
SP - 1006
EP - 1011
BT - Materials Science Forum - Nanomaterials by Severe Plastic Deformation 4 - 4th International Conference on Nanomaterials by Severe Plastic Deformation
PB - Trans Tech Publications Ltd
T2 - 4th International Conference on Nanomaterials by Severe Plastic Deformation
Y2 - 18 August 2008 through 22 August 2008
ER -