2009 Fiscal Year Final Research Report
Improvement of thermoelectric properties of chimney-ladder compounds by controlling compositional/structural grade
| Project/Area Number |
20860049
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| Research Category |
Grant-in-Aid for Young Scientists (Start-up)
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| Allocation Type | Single-year Grants |
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| Research Field |
Physical properties of metals
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| Research Institution | Kyoto University |
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Principal Investigator |
OKAMOTO Norihiko Kyoto University, 工学研究科, 助教 (60505692)
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| Research Collaborator |
INUI Haruyuki 京都大学, 工学研究科, 教授 (30213135)
TANAKA Katsushi 京都大学, 工学研究科, 准教授 (30236575)
KISHIDA Kyosuke 京都大学, 工学研究科, 准教授 (20354178)
ADACHI Hiroki 京都大学, 工学研究科, 助教 (00335192)
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| Project Period (FY) |
2008 – 2009
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| Keywords | 熱電変換材料 / 格子熱伝導率 / 界面熱抵抗 / フォノン散乱 / 透過電子顕微鏡 |
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| Research Abstract |
Phase relationships of manganese-substituted ruthenium sesquisilicide alloys have been investigated by using x-ray powder diffraction, scanning and transmission electron microscopy. A series of chimney-ladder phases Ru_<1-x>Mn_xSi_y are formed over a wide compositional range between Ru_2Si_3 and Mn_4Si_7. Directionally solidified chimney-ladder compounds in the Ru-Mn-Si system exhibit a microstructure containing columnar domains of different chimney-ladder phases with compositional interfaces between adjacent phases. Despite a compositional variation, the transition-metal (Ru/Mn) sublattice is continuous over the interface while the Si sublattice is discontinuous. The lattice thermal conductivity of the directionally solidified alloys along the transverse direction decreases by increasing the density of the compositional interfaces while the electrical properties are preserved.
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