- Thermoelectric Properties of Bi2Te2.7Se0.3 Powder Synthesized by an Oxide-Reduction Process
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Bae-Gun Park, Gil-Geun Lee, Woo-Yeol Kim, Gook-Hyun Ha
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J Korean Powder Metall Inst. 2011;18(5):437-442.
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DOI: https://doi.org/10.4150/KPMI.2011.18.5.437
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 Abstract
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- The present study focused on the synthesis of Bi-Te-Se-based powder by an oxide-reduction process, and analysis of the thermoelectric properties of the synthesized powder. The phase structure, chemical composition, and morphology of the synthesized powder were analyzed by XRD, EPMA and SEM. The synthesized powder was sintered by spark plasma sintering. The thermoelectric properties of the sintered body were evaluated by measuring its Seebeck coefficient, electrical resistivity, and thermal conductivity. Bi_2Te_2.7Se_0.3 powder was synthesized from a mixture of Bi_2O_3, TeO_2, and SeO_2 powders by mechanical milling, calcination, and reduction. The sintered body of the synthesized powder exhibited n-type thermoelectric characteristics. The thermoelectric properties of the sintered bodies depend on the reduction temperature. The Seebeck coefficient and electrical resistivity of the sintered body were increased with increasing reduction temperature. The sintered body of the Bi_2Te_2.7Se_0.3 powder synthesized at 360°C showed about 0.5 of the figure of merit (ZT) at room temperature.
- Thermoelectric Properties of Bi0.4Sb1.6Te3 Sintered Body Fabricated by Mechanical Grinding Process
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Gil-Geun Lee, Sung-Chul Shin, Woo-Yeol Kim, Gook-Hyun Ha
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J Korean Powder Metall Inst. 2006;13(5):313-320.
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DOI: https://doi.org/10.4150/KPMI.2006.13.5.313
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Abstract
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- The present study is to analyze the thermoelectric properties of Bi_0.4Sb_1.6Te_3 thermoelectric materials fabricated by the mechanical grinding process. The Bi_0.4Sb_1.6Te_3 powders were prepared by the combination of mechanical milling and reduction treating methods using simply crushed pre-alloyed Bi_0.4Sb_1.6Te_3 powder. The mechanical milling was carried out using the tumbler-ball mill and planetary ball mill. The tumbler-ball milling had an effect on the carrier mobility rather than the carrier concentration, whereas, the latter on the carrier concentration. The specific electric resistivity and Seebeck coefficient decreased with increasing the reduction-heat-treatment time. The thermal conductivity continuously increased with increasing the reduction-heat-treatment time. The figure of merit of the Bi_0.4Sb_1.6Te_3 sintered body prepared by the mechanical grinding process showed higher value than one of the sintered body of the simply crushed powder.
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