| 概 要 |
分子科学研究所外国人運営顧問のCastleman教授が１３日から１７日の予定で来所されます。
昨年は、ご講演を頂く時間が無かったのですが、今回、「THE PROSPECT OF DESIGNER MATERIALS VIA CLUSTER ASSEMBLY: THE NEXT FRONTIER IN NANOSCALE SCIENCE」という題目でお話しして頂くことになりました。
Currently, there is extensive interest in systems of finite size, as they often give rise to unique properties that differ from those of an extended solid or the individual molecular constituents of which they are comprised. Particularly interesting are nanoscale systems whose composition can be selectively chosen, and ones whose individual characteristics can be retained when assembled as an extended material.
A major long-term goal of our research in this area is to develop ways of tailoring the design and formation of new nanoscale materials of chosen electronic, optical and catalytic properties. Recent success has been obtained in producing alloy cluster species of specific size and composition that simulate various elements of the periodic table, a topic which will be discussed in detail.
As a complementary approach to conventional surface studies widely used in the field of catalysis, it is becoming increasingly recognized that cluster science can help elucidate the physical and chemical properties of condensed phase catalysts and can provide detailed information on the mechanisms of reactions and the nature of various reaction sites that enables certain catalytic materials to be especially effective. In addition, the possible direct use of clusters as catalysts has aroused interest due to the difference in reactivities often observed for nanoscale materials compared to conventional bulk catalysts. Our latest findings on transition metal oxides and metallic clusters will be presented. In related studies, we are employing femtosecond pump-probe techniques to explore the electronic properties of the clusters, including their excitation and relaxation behavior, which is providing insights into their evolving band structure. Findings pertaining to the electronic characteristics of metal-carbon systems will also be discussed.
References:
[1] D. E. Bergeron, A. W. Castleman, Jr., T. Morisato, and S. N. Khanna, Science, 304, 84-87 (2004).
[2] D. E. Bergeron, P. J. Roach, A. W. Castleman, Jr., N. O. Jones, and S. N. Khanna, Science, 307, 231-235 (2005).
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