21COE プログラム「機械システム・イノベーション」平成19年度第5回公開セミナーを開催いたします。
Hans Kuzmany先生は、カーボンナノチューブのラマンなどの分光研究の第一人者であると同時に、
今年度まで20年以上にわたってInternational Winterschool on Electronic Properties of Novel MaterialsをKirchbergで主催され、
フラーレンやナノチューブ関連の分光に関するもっとも重要な国際会議に育ててきました。
今回、東工大の斎藤晋先生の招きで来日の機会に東大で下記の講演をいただけることになりました。
今回のセミナーでは高度なラマン分光を用いたカーボンナノチューブの生成に関する最新の研究内容をお話しいただく予定です。
ふるってご参加いただきますようどうぞ宜しくお願い申し上げます。
講師 |
Professor Hans Kuzmany (Department of Physics, University of Vienna, Austria) |
題目 |
The Growth of DWCNTs from the Precursor Route |
日時 |
2007年10月22日(月)14:00〜15:30 |
場所 |
工学部2号館・電気系会議室4(112C1) |
講演要旨 |
Double-walled carbon nanotubes (DWCNTs) are a special tube species intermediate between single-walled carbon nanotubes and multi-walled carbon nanotubes. They attract recently particular attention, since they exhibit several properties which are of scientific and technological relevance. DWCNTs can be grown either directly in a CVD process or from precursor routes. In the latter case either peapods as a starting material or a catalytic process inside the tubes can be used.
We report on detailed Raman, x-ray scattering, HRTEM, and photoemission studies performed for the precursor routes. For the peapod as a starting material an analysis with 13C labelled fullerenes the growth process is found to be local which means immediately on the cage. Stone-Wales transformations play a crucial role. They lead to an intermediate phase between the fullerenes and the final inner-shell tube. For the catalytic process ferrocene is used as a starting material. Eventually iron carbide is the active catalyst. Tube growth can proceed for temperatures as low as 600 K. There is evidence for charge transfer between the catalyst and the outer-shell tubes. The final DWCNT product is different for the two precursor routes even for equal starting material. Some characteristic differences to the CVD grown tubes will be elucidated.
Work supported by the Austrian Science Foundation Project 17345 and I80-N20 (IMPRESS), by the HRTEM facilities at AIST in Japan, and by the Alexander von Humboldt foundation in Germany.
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