Effect of mechanical deformation on thermoelectric properties of p-Type (Bi 0.225Sb 0.775)2Te3Alloys

Sung Jin Jung, Seong Keun Kim, Hyung Ho Park, Dow Bin Hyun, Seung Hyub Baek, Jin Sang Kim

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

The effect of mechanical deformation and annealing on thermoelectric properties of p-type (Bi0.225Sb0.775)Te3 was performed. The ingots were prepared by melting, followed by quenching method using source materials with compositions of (Bi0.225Sb 0.775)2Te3. Rectangular shaped specimens (5 × 5 × 12 mm3) were cut from ingots and then cold-pressed at 700 MPa for 2 to 20 times by changing the press direction perpendicular to previous one. The cold-pressed samples have been annealed in a quartz ampoule at 573 K. The grain size of the samples was controlled by the number of cold-pressing process and annealing time. Fine grain structure with a grain size of not more than 10 m is obtained in highly deformed samples. The Seebeck coefficient of the deformed samples were gradually increased with annealing and converged to the similar value of about 225 V/K after 30 hrs. The small grain size in highly deformed sample enables a rapid increase of Seebeck coefficient with annealing time (∼2 hrs.), indicating that the thermal energy needed to recrystallize in highly deformed specimens is lower than that in low deformed specimens. Z values are rapidly increased with annealing time especially in highly deformed alloys, and converge to about 3.0 × 10-3/K at room temperature. A higher thermoelectric performance could be expected by the optimization of composition and microstructural adjustment. The present study experimentally demonstrates a simple and cost-effective method for fabricating Bi-Te-based alloys with higher thermoelectric performance.

Original languageEnglish
Article number868540
JournalJournal of Nanomaterials
Volume2013
DOIs
Publication statusPublished - 2013 Dec 1

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Annealing
Seebeck coefficient
Ingots
Quartz
Crystal microstructure
Thermal energy
Chemical analysis
Quenching
Melting
Costs
Temperature

All Science Journal Classification (ASJC) codes

  • Materials Science(all)

Cite this

Jung, Sung Jin ; Kim, Seong Keun ; Park, Hyung Ho ; Hyun, Dow Bin ; Baek, Seung Hyub ; Kim, Jin Sang. / Effect of mechanical deformation on thermoelectric properties of p-Type (Bi 0.225Sb 0.775)2Te3Alloys. In: Journal of Nanomaterials. 2013 ; Vol. 2013.
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Effect of mechanical deformation on thermoelectric properties of p-Type (Bi 0.225Sb 0.775)2Te3Alloys. / Jung, Sung Jin; Kim, Seong Keun; Park, Hyung Ho; Hyun, Dow Bin; Baek, Seung Hyub; Kim, Jin Sang.

In: Journal of Nanomaterials, Vol. 2013, 868540, 01.12.2013.

Research output: Contribution to journalArticle

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AU - Kim, Seong Keun

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AU - Kim, Jin Sang

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