Kaoru Kimura Group
Materials Design and Processing [Nano-Space Function Design]
Impression in the edge of twenties is
entire life’s treasure in the field of science.
The discovery of "Quasicrystal" gave a great impression to me, and I have continued to investigate it until now. It takes 27 years from the first discovery in 1984 to get Novel Prize in 2011 after establishment as a big concept of solid state structure, which takes a place beside "Crystal" and "Amorphous".
In "Quasicrystal", "Semiconductor" and "Insulator" have not yet been discovered. It is remaining as a basic problem in the solid state physics, whether they exist or not. On the other hand, the development of high performance "thermoelectric material" has a potential to be a key technology, which can contribute to the energy problem and the environmental one. We are proposing that "Semiconducting Quasicrystal" should be a great candidate for thermoelectric material.
Professor Kaoru Kimura
- 1979 Graduation, Department of Physics, the University of Tokyo
- 1984 PhD, Department of Physics, the University of Tokyo
- 1984 Research associate, Institute for Solid State Physics, the University of Tokyo
- 1989 Lecturer, Department of Materials Science, the University of Tokyo
- 1992 Associate professor, Department of Materials Science, the University of Tokyo
- 1993 (～1994) Visiting researcher, Gerhardt Mercator University, Duisburg, Germany
- 1994 Associate professor, Department of Materials Engineering, the University of Tokyo
- 1999 Professor, Department of Advanced Material Science, the University of Tokyo
Introduction of the study
We proposed "metallic-covalent bonding conversion" due to slight structural changes in the boron and aluminum icosahedral clusters, and have been experimentally demonstrating this conversion. By discussing the properties of both the aluminum-based quasicrystalline alloy and the boron-based semiconductor, which conventionally have been discussed separately in the fields of metals and semiconductors, we have been successful in formulating a unified picture of icosahedral cluster solids. This is an example of academic fusion. We are currently involved in evaluating this group of materials as an intermediate material between metals and semiconductors and as solids with a complex structure (nanoscale complex material), to develop thermoelectric conversion materials and high-resistance chip material. We also began research on clusters isolated in space.
Comparison of multiple-shell structures for boron- and aluminum-based icosahedral cluster solids.
The vacant sites of the former are occupied for the latter as shown by the dotted circle. This induces the bonding conversion from covalent to metallic.
Message from a senior
Atsuro Sumiyoshi and Koichi Kitahara
Professor Kimura is a mild parson. Because he is respecting self-initiative of students, we can determine many things by ourselves in our research activity. He supervises us to give a definite comment from the wide view based on his experience. We think that he is an ideal professor for self-active students.
In our laboratory, we are doing material development and basic evaluation based on the view of applied solid state physics (nano-space function design). Because there are calm atmosphere in our laboratory, it is easy to ask and discuss many things. We, laboratory members, are absorbing knowledge and technique each other, as a result, we can focus on the most important point of the research theme.