He is developing novel functions in covalently bonded, so-called atomic network compounds, namely, compounds in which the basic crystal structure is composed of atomic clusters or 2D atomic nets. For example, boron network compounds have not been as well developed as their carbon counterparts. However, by utilizing boron's electron deficient atomic networks and affinity for metal elements and through control of the network order, he has discovered newly functional magnetic and thermoelectric compounds.

Development of high temperature thermoelectric materials

He has discovered the long awaited n-type counterpart to p-type boron carbide, which is an excellent high temperature thermoelectric compound. Development of effective thermoelectric compounds is imperative because of the rapidly approaching limit of classical energy usages. A huge amount of wasted energy exists in the high temperature region and materials which can convert this to useful electricity will have a great beneficial impact on society.

Magnetism of boron-containing compounds

He has elucidated the origin of the high temperature ferromagnetism reported in boron based compounds like CaB6, which was reported in Nature and Science and engendered an intense interest throughout the world. He has also found that the boron icosahedron can function as a novel mediator of magnetic interaction, creating unexpectedly strong magnetic behavior in magnetically dilute f-electron insulator systems.