2010 Fiscal Year Final Research Report
Anharmonicities on Anomalous Phonon Mode in Thermal Expansion in Tungsten Oxide Crystals
| Project/Area Number |
20540322
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Condensed matter physics I
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| Research Institution | Kushiro National College of Technology |
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Principal Investigator |
SUDA Jun 釧路工業高等専門学校, 電気工学科, 教授 (20369903)
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| Co-Investigator(Kenkyū-buntansha) |
KAMISHIMA Osamu 摂南大学, 工学部, 准教授 (90321984)
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| Co-Investigator(Renkei-kenkyūsha) |
HATTORI Takeshi 東京理科大学, 理学部, 教授 (20029234)
KAWAMURA Junichi 東北大学, 多元物質科学研究所, 所長,教授 (50142683)
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| Research Collaborator |
ZVEREV G. Prokhorov General Physics Institute Russian Academy of Sciences, Laser Materials and Technology Research Center, Raman Lasers Division Head
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| Project Period (FY) |
2008 – 2010
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| Keywords | フォノン / 格子力学 / 第一原理計算 / 熱膨張異常 / 灰重石構造 / タングステン酸結晶 |
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| Research Abstract |
The phonon-dispersion relations in the scheelite type of tungsten oxide crystals are calculated using the Lattice dynamical approach with the first-principle calculations. Raman spectra in these crsytals were measured in the broadened temperature range. The temperature dependence of linewidth of the Raman active modes were analyzed using this approach. We found that a lowest-frequency(anomalous) mode having a negative value ofγj and a clearly large phonon band gap exists in the DOS. The different behaviors in the case of temperature broadening of several modes can be attributed to this band gap.
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