Emeritus Prof. Akiko Kobayashi Wins the 2009 L'ORÉAL-UNESCO Awards for Women in Science
Prof. Akiko Kobayashi
Akiko Kobayashi, Professor Emeritus (currently a professor at Nihon University), has been selected as one of the 5 recipients of the 2009 L'ORÉAL-UNESCO Awards for Women in Science. The L'ORÉAL-UNESCO Awards were established in 1998 to honor women scientists who made outstanding contributions to the scientific progress on a global level. The Award laureates are selected by the screening committee composed of global intellectuals including Nobel laureates; every year 5 Award laureates are selected from five continents. Prof. Kobayashi is the 3rd laureate from Japan following Tsuneko Okasaki (in 2000) and Fumiko Yonezawa (in 2005). The award ceremony will be held at the UNESCO headquarters in Paris on March 5, 2009.
Prof. Kobayashi succeeded in designing and creating single-component molecular metals for the first time in the world. The molecular metals that had been found so far were made up of more than 2 kinds of molecular species; for the molecules that form a conduction path to generate charge carriers such as electrons or holes in the path, they needed other molecular species that exchange electrons between the molecules that form the path and them. For this reason, molecular crystals that consist of single-molecules were considered to be the representative of insulators. On the basis of her many years of research on molecular metals, however, Dr. Kobayashi predicted the following fact; inside the nickel complex (Ni(tmdt)2) that holds ligands with spread π-electrons that contain a lot of sulfur atoms, the HOMO-LUMO gap of molecules is small, and through the overlapped HOMO band and LUMO band attained by the strong interaction among the molecules in molecular crystals, just an assembly of single-kind molecules would form metallic crystals as we can see in the metallic element like copper. Then, she successfully realized the first metallic crystal ever composed of molecules of a single-species [Science 291, 285-287 (2001)]. The room temperature conductivity of this Ni(tmdt)2 single crystal is 400 S cm-1 and it shows metallic temperature dependency of down to 0.6 K. In this matter, magnetic quantum oscillations were observed and an experimental proof was obtained showing the fact that this molecular crystal is a metal that has Fermi surfaces which is the characteristic feature of a metal.
This achievement has changed the concept of molecules and made an outstanding contribution to the development of material science field.
Prof. Kobayashi has been awarded for: contribution to the development of molecular conductors and the design and synthesis of a single-component molecular metal.