Unlocking the future of big data and IoT society through basic research in chemistry

Asuka Namai is dedicated to basic research in chemistry and has been investigating new materials for over ten years. These new materials have enormous potential to unlock the future of big data and IoT society.

――What kind of research are you doing?

I am researching nanosized iron oxides (Fe₂O₃). There are various types of iron oxides with different crystalline structures. Iron oxides in nature include alpha iron oxide, which is called red rust, and gamma iron oxide, a kind of iron sands. The type that I’m investigating, epsilon iron oxide, was first synthesized in a single-phase in 2004 by Shin-ichi Ohkoshi, a professor in the School of Science’s Department of Chemistry, using a chemical nanoparticle synthesis method. I’ve been conducting research on this material with Professor Ohkoshi since 2007.

――What are the characteristics of epsilon iron oxide?

Epsilon iron oxide has magnetic properties and a large coercive field that is less susceptible to magnetic fields. Ferrite magnets made of iron oxide are the most widely produced magnets, cost effective, and have excellent chemical stability, but they generally do not have a very large coercive field. On the other hand, rare-earth magnets, which have a large coercive field, are expensive due to their uneven distribution and a shortage of rare earth resources that are used as materials. Ferrite magnets made from epsilon iron oxides have a coercive field that is comparable to those of rare-earth magnets, which expands their possibilities for use. Finding a new physical property in an ordinary material such as iron oxide has a tremendous scientific impact.

――I heard there are high expectations for the application of ferrite magnets.

We are currently conducting applied research with companies and looking at two applications of ferrite magnets in information and communication fields. One is the application of magnetic tape as a next-generation recording material. With the arrival of the big data era, demand for magnetic tape as a high-capacity, low cost, and long-term storage device is rising, and there is growing demand for even higher capacities. As epsilon iron oxide has a large coercive field even when its particle size is less than 10 nanometers, it is promising as a recording material.

The other is the use of ferrite magnets as an electromagnetic wave absorbing material. In recent years, radio waves called millimeter waves, with a frequency band between 30-300 gigahertz, have started to be used in automotive radars for advanced driver assistance systems and next-generation wireless communication technology. Absorbent material is needed to reduce noise caused by electromagnetic interference and for security purposes, so we intend to use epsilon iron oxide, which has millimeter wave absorption properties, to accomplish this.

Currently, I am studying radio frequency engineering and have been named as an inventor in over 70 patent applications. Although I am still focusing on basic research in chemistry, I’m astonished by how things turned out.

――What made you decide to become a researcher?

I became increasingly interested in the research that I did during classes in the Faculty of Science, so I enrolled in the Faculty in my third year of undergraduate school. I am thankful that I can continue doing this research now as an assistant professor*.

“Chemistry is the only discipline where you can create new materials.” When I heard these words during a class at Komaba Campus, I decided that I would study chemistry. You can study chemistry in the School of Engineering; however, I was drawn to science, which plants and nurtures seeds by creating something new, rather than engineering, which focuses on creating something that meets the needs of society.

――From the perspective of a long-term member, what do you find appealing about the School of Science?

The School of Science has leading professors and excellent research facilities. For instance, whenever I visit universities abroad for collaborative research projects, I realize how fortunate I am to be able to conduct research at the School of Science. Similarly, when researchers from overseas come to visit us, they are always surprised by how well-equipped our facilities are. Students can also freely use most of these facilities, which is one reason why I would like to encourage students to tackle research that can only be done at the University of Tokyo’s School of Science.

Interview and text: Masatsugu Kayahara (Translation: Kristina Awatsu)
Photography: Junichi Kaizuka

Originally published in The School of Science Brochure 2018

NAMAI Asuka

Department of Chemistry Alumna
Assistant Professor*, Department of Chemistry, School of Science

Asuka Namai graduated from the Department of Chemistry at the University of Tokyo in 2008 and obtained her master’s degree from the Graduate Department of Chemistry, The University of Tokyo, in 2010, and obtained her PhD degree in 2014. She became a project assistant professor in 2011, and became an assistant professor in 2012. She has received several awards, including the University of Tokyo’s President’s Award in 2009 and the Inoue Research Award for Young Scientists in 2016.
*Asuka Namai became an associate professor in 2019.