Effect of Heat Treatment on the Thermoelectric Properties of Bismuth–Antimony–Telluride Prepared by Mechanical Deformation and Mechanical Alloying

• Published in: Journal of electronic materials 2014-06, Vol.43 (6), p.2255-2261
• Main Authors: Lee, Deuk-Hee, Lee, Jae-Uk, Jung, Sung-Jin, Baek, Seung-Hyub, Kim, Ju-Heon, Kim, Dong-Ik, Hyun, Dow-Bin, Kim, Jin-Sang
• Format: Article
• Language: English
• Subjects: Alloys; Annealing; Applied sciences; Characterization and Evaluation of Materials; Chemistry and Materials Science; Cold working, work hardening; annealing, quenching, tempering, recovery, and recrystallization; textures; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Conductivity phenomena in semiconductors and insulators; Cross-disciplinary physics: materials science; rheology; Deformation; Electric properties; Electronic transport in condensed matter; Electronics and Microelectronics; Exact sciences and technology; Heat treating; Heat treatment; Instrumentation; Materials Science; Mechanical engineering; Metals. Metallurgy; Optical and Electronic Materials; Physics; Powder metallurgy; Powder metallurgy. Composite materials; Production techniques; Solid State Physics; Technology; Thermoelectric and thermomagnetic effects; Treatment of materials and its effects on microstructure and properties
• ISSN: 0361-5235; 1543-186X
• DOI: 10.1007/s11664-014-3037-1

In this work, p -type 20%Bi 2 Te 3 –80%Sb 2 Te 3 bulk thermoelectric (TE) materials were prepared by mechanical deformation (MD) of pre-melted ingot and by mechanical alloying (MA) of elemental Bi, Sb, and Te granules followed by cold-pressing. The dependence on annealing time of changes of microstructure and TE properties of the prepared samples, including Seebeck coefficient, electrical resistivity, thermal conductivity, and figure-of-merit, was investigated. For both samples, saturation of the Seebeck coefficient and electrical resistivity were observed after annealing for 1 h at 380°C. It is suggested that energy stored in samples prepared by both MA and MD facilitated their recrystallization within short annealing times. The 20%Bi 2 Te 3 –80%Sb 2 Te 3 sample prepared by MA followed by heat treatment had higher a Seebeck coefficient and electrical resistivity than specimens fabricated by MD. Maximum figures-of-merit of 3.00 × 10 −3 /K and 2.85 × 10 −3 /K were achieved for samples prepared by MA and MD, respectively.