Texture control of bulk mechanical alloyed Bi-Te thermoelectric materials via shear extrusion

Sang Seok Kim, Tatsuhiko Aizawa

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

Shear extrusion processing with combination of bulk mechanical alloying (BMA) is employed to yield the p-type (Bi2Te3)0.2(Sb 2Te3)0.8 and n-type (Bi2Se 3)0.05(Bi2Te3)0.95 Bi-Te thermoelectric materials from elemental granules. The shear-extruded p-type, n-type Bi-Te compounds have the preferred orientation factor (F) to anisotropic crystallographic structure : FP(max)= 0.63, Fn(max)= 0.67. For p-type, in case of the single crystal, F = 1.0 and p min = 0.995x10-5 Ωm. On the contrary, hot pressed sample has F = 0.02 and p = p random = 2.110xl0-5 Ω m. In case of the shear extruded sample, 0.5<F<0.63. This high F value assures that the measured resistivity becomes nearly equal to lxlO-5 Ωm, the resistivity for the single crystals with F = 1. Maximum power factors of p-type, n-type materials are achieved to 4.33xl0-3(W/mK2), 3.31xl0-3(W/mK2) even without any dopants. The bending strength of the material produced is also improved to be the range of 120-160MPa, six times larger than that for zone-melted specimen.

Original languageEnglish
Pages (from-to)197-200
Number of pages4
JournalJournal of Metastable and Nanocrystalline Materials
Volume24-25
DOIs
Publication statusPublished - 2005
Externally publishedYes

Fingerprint

thermoelectric materials
Extrusion
textures
Textures
shear
Single crystals
electrical resistivity
flexural strength
single crystals
Mechanical alloying
Bending strength
alloying
Doping (additives)
Processing

Keywords

  • Anisotropy
  • Bi-Te
  • N-type
  • P-type
  • Shear extrusion
  • Thermoelectric materials

ASJC Scopus subject areas

  • Materials Science(all)
  • Physical and Theoretical Chemistry
  • Condensed Matter Physics

Cite this

Texture control of bulk mechanical alloyed Bi-Te thermoelectric materials via shear extrusion. / Kim, Sang Seok; Aizawa, Tatsuhiko.

In: Journal of Metastable and Nanocrystalline Materials, Vol. 24-25, 2005, p. 197-200.

Research output: Contribution to journalArticle

@article{ed16ff7bebed495685afa7e90c3f1b74,
title = "Texture control of bulk mechanical alloyed Bi-Te thermoelectric materials via shear extrusion",
abstract = "Shear extrusion processing with combination of bulk mechanical alloying (BMA) is employed to yield the p-type (Bi2Te3)0.2(Sb 2Te3)0.8 and n-type (Bi2Se 3)0.05(Bi2Te3)0.95 Bi-Te thermoelectric materials from elemental granules. The shear-extruded p-type, n-type Bi-Te compounds have the preferred orientation factor (F) to anisotropic crystallographic structure : FP(max)= 0.63, Fn(max)= 0.67. For p-type, in case of the single crystal, F = 1.0 and p min = 0.995x10-5 Ωm. On the contrary, hot pressed sample has F = 0.02 and p = p random = 2.110xl0-5 Ω m. In case of the shear extruded sample, 0.5<F<0.63. This high F value assures that the measured resistivity becomes nearly equal to lxlO-5 Ωm, the resistivity for the single crystals with F = 1. Maximum power factors of p-type, n-type materials are achieved to 4.33xl0-3(W/mK2), 3.31xl0-3(W/mK2) even without any dopants. The bending strength of the material produced is also improved to be the range of 120-160MPa, six times larger than that for zone-melted specimen.",
keywords = "Anisotropy, Bi-Te, N-type, P-type, Shear extrusion, Thermoelectric materials",
author = "Kim, {Sang Seok} and Tatsuhiko Aizawa",
year = "2005",
doi = "10.4028/www.scientific.net/JMNM.24-25.197",
language = "English",
volume = "24-25",
pages = "197--200",
journal = "Journal of Metastable and Nanocrystalline Materials",
issn = "1422-6375",
publisher = "Trans Tech Publications",

}

TY - JOUR

T1 - Texture control of bulk mechanical alloyed Bi-Te thermoelectric materials via shear extrusion

AU - Kim, Sang Seok

AU - Aizawa, Tatsuhiko

PY - 2005

Y1 - 2005

N2 - Shear extrusion processing with combination of bulk mechanical alloying (BMA) is employed to yield the p-type (Bi2Te3)0.2(Sb 2Te3)0.8 and n-type (Bi2Se 3)0.05(Bi2Te3)0.95 Bi-Te thermoelectric materials from elemental granules. The shear-extruded p-type, n-type Bi-Te compounds have the preferred orientation factor (F) to anisotropic crystallographic structure : FP(max)= 0.63, Fn(max)= 0.67. For p-type, in case of the single crystal, F = 1.0 and p min = 0.995x10-5 Ωm. On the contrary, hot pressed sample has F = 0.02 and p = p random = 2.110xl0-5 Ω m. In case of the shear extruded sample, 0.5<F<0.63. This high F value assures that the measured resistivity becomes nearly equal to lxlO-5 Ωm, the resistivity for the single crystals with F = 1. Maximum power factors of p-type, n-type materials are achieved to 4.33xl0-3(W/mK2), 3.31xl0-3(W/mK2) even without any dopants. The bending strength of the material produced is also improved to be the range of 120-160MPa, six times larger than that for zone-melted specimen.

AB - Shear extrusion processing with combination of bulk mechanical alloying (BMA) is employed to yield the p-type (Bi2Te3)0.2(Sb 2Te3)0.8 and n-type (Bi2Se 3)0.05(Bi2Te3)0.95 Bi-Te thermoelectric materials from elemental granules. The shear-extruded p-type, n-type Bi-Te compounds have the preferred orientation factor (F) to anisotropic crystallographic structure : FP(max)= 0.63, Fn(max)= 0.67. For p-type, in case of the single crystal, F = 1.0 and p min = 0.995x10-5 Ωm. On the contrary, hot pressed sample has F = 0.02 and p = p random = 2.110xl0-5 Ω m. In case of the shear extruded sample, 0.5<F<0.63. This high F value assures that the measured resistivity becomes nearly equal to lxlO-5 Ωm, the resistivity for the single crystals with F = 1. Maximum power factors of p-type, n-type materials are achieved to 4.33xl0-3(W/mK2), 3.31xl0-3(W/mK2) even without any dopants. The bending strength of the material produced is also improved to be the range of 120-160MPa, six times larger than that for zone-melted specimen.

KW - Anisotropy

KW - Bi-Te

KW - N-type

KW - P-type

KW - Shear extrusion

KW - Thermoelectric materials

UR - http://www.scopus.com/inward/record.url?scp=63849206853&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=63849206853&partnerID=8YFLogxK

U2 - 10.4028/www.scientific.net/JMNM.24-25.197

DO - 10.4028/www.scientific.net/JMNM.24-25.197

M3 - Article

AN - SCOPUS:63849206853

VL - 24-25

SP - 197

EP - 200

JO - Journal of Metastable and Nanocrystalline Materials

JF - Journal of Metastable and Nanocrystalline Materials

SN - 1422-6375

ER -