Effects of Y2O3 and Y Addition on Thermoelectric Properties of β-FeSi2 Synthesized by Mechanical Alloying and Hot Pressing

• Ito Mikio

  Department of Materials Science and Processing, Graduate School of Engineering, Osaka University

• Tada Tomoyuki

  Department of Materials Science and Processing, Graduate School of Engineering, Osaka University

• Hara Shigeta

  Department of Materials Science and Processing, Graduate School of Engineering, Osaka University

書誌事項

タイトル別名

• Effects of Y<SUB>2</SUB>O<SUB>3</SUB> and Y Addition on Thermoelectric Properties of β-FeSi<SUB>2</SUB> Synthesized by Mechanical Alloying and Hot Pressing
• Effects of Y2O3 and Y Addition on Thermoelectric Properties of ベータ FeSi2 Synthesized by Mechanical Alloying and Hot Pressing
• Effects of Y<SUB>2</SUB>O<SUB>3</SUB> and Y Addition on Thermoelectric Properties of &beta;-FeSi<SUB>2</SUB> Synthesized by Mechanical Alloying and Hot Pressing

抄録

The n-type Fe_0.98Co_0.02Si₂ compacts with Y₂O₃ (1—6 mass%) dispersion were synthesized by mechanical alloying with Y₂O₃ powder and subsequent hot pressing. The effects of Y₂O₃ addition on the thermoelectric properties of the β-FeSi₂ were investigated. The microstructures of the hot pressed samples were observed by transmission electron microscopy (TEM). The TEM observation showed that the fine Y₂O₃ particles around 10 nm in size were dispersed in the β phase matrix by mechanical alloying, resulting in a significant reduction in the thermal conductivity due to enhancing phonon scattering. The Seebeck coefficient was also enhanced by Y₂O₃ addition especially below 800 K, corresponding to the extrinsic conductive region of the β-FeSi₂. Consequently, the figure of merit was significantly improved by 2 mass% Y₂O₃ addition. The chemical composition of these samples with Y₂O₃ addition was examined by the energy dispersive X-ray spectroscopy (EDX). The EDX analysis revealed that the added Y₂O₃ was partially decomposed and a small amount of Y was dissolved in the β phase matrix. Based on this fact, the enhancement of the Seebeck coefficient caused by Y₂O₃ addition is considered to be due to reduction in carrier concentration resulted from this Y solution as a p-type dopant in the β phase matrix, and the behavior of the Seebeck coefficient was found to be well consistent with that of the Y-doped samples synthesized by Y powder addition.

収録刊行物

• MATERIALS TRANSACTIONS

  MATERIALS TRANSACTIONS 45 (9), 2916-2921, 2004

  公益社団法人 日本金属学会

キーワード

• iron disilicide
• mechanical alloying
• Seebeck coefficient
• thermal conductivity
• rare-earth oxide dispersion

詳細情報

• CRID: 1390001204249057664
• NII論文ID: 130004452589
• NII論文ID: 10013580099
• NII書誌ID: AA1151294X
• DOI: 10.2320/matertrans.45.2916
• COI: 1:CAS:528:DC%2BD2cXpvV2gsb8%3D
• ISSN: 13475320
• ISSN: 13459678
• NDL書誌ID: 7088302
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I7088302
• Web Site: https://www.jstage.jst.go.jp/article/matertrans/45/9/45_9_2916/_pdf
• 本文言語コード: en
• データソース種別:
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  • KAKEN
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