Materials Research Activities

Interview Naohiro SOGA

Interview Naohiro SOGA

National Institute of Advanced Industrial Science and Technology

Tokyo, October 29, 2002

Short biography of Prof. Soga.

Hervé Arribart (HA): In which discipline did you take your degree? YourPhD?

Naohiro Soga (NS): I got my PhD in Glass Science. It belonged to Inorganic Structural Chemistry Laboratory in Department of Industrial Chemistry (or applied chemistry, it is about the same in Japan), Faculty of Engineering. I came into Glass Science as a senior student under Professor Sawai. He was probably the first who taught Glass Science in Japan. He went to Germany before WW II. As the research topics, Professor Sawai gave me three options: i) Glass Science, ii) Glass Technology or industry iii) Refractory. There were 3 associate professors working with him on these topics. One was Professor Tashiro who spent three years on Glass Science at Penn State as a Fulbright Fellow and just came back to Japan. It was a new field and so I thought that I should start my senior thesis in Glass Science.

HA: Who chose your PhD subject?

NS: Professor Tashiro guided me to choose the subject. Professor Sawai retired in the first year of my master course. Then Professor Tashiro became my thesis advisor.

HA: I also noticed the name of Professor Sakka

NS: Professor Sakka was a Research Associate under Pr. Sawai when I started my senior year, and later became Associate Professor under Pr. Tashiro. At that time, Japanese science and technology were far behind from USA, and we had to import all kinds of science and technology. When Professor Tashiro came back, he started work on irradiation effect on glass. In this field, Professor Kriedl was active. Then we bought a cobalt irradiator to follow his work. Dr. Sakka and I were working together. Then came Dr Donald Stookey's photosensitive glass and pyroceram, which involved nucleation and crystallization in glass. Professor Tashiro set up three projects on these subjects and divided them to three people working under him. They are:

  1. Fundamental research on nucleation and crystallization of glass. This aspect went to Sakka.
  2. Phenomenological and theoretical approach to photosensitive glasses. This was for me.
  3. Development of new glass ceramics. Professor Tashiro had some connection with NEG (Nippon Electric Glass Co.), then a small company. They were interested in glass ceramics and cooperated with him in its development. Mr Wada, who came in Tashiro's Lab a year before and joined later NEG, was on that project.

That is a reason why I went into the photosensitive glass, after working on gamma ray and UV radiation effects in glasses.

HA: Did you keep contacts with Dr Stookey.

Yes, but through Professor Tashiro at that time. In 1962, I attended my first international glass conference (the International Cogress on Glass) in Washington with Professor Tashiro. After the Congress, Professor Tashiro toured around the United States and gave a talk at Corning, Alfred University and other places. They were interested in how silver colloids formed from ionic state through atomic state, mechanism of which I studied. I made a special high temperature cell for spectrophotometer and followed the changes in optical absorption due to cerium ions’ valence change and coagulation of silver atoms to colloids.

HA: Did you use the expression "materials science" in Japan in these years?

NS: No. There was no concept of materials science covering various kinds of materials. It was "Glass and Ceramics" as a part of applied chemistry.

Bernadette Bensaude-Vincent (BBV) When did this expression "materials science" come into use in Japan?

NS: Probably in the 1970s after I came back from USA and it became popular in the 1980s. I was exposed to the concept that glass and ceramics are a part of materials when I was in USA. Going back to the past, after getting my PhD, I was invited to join the American-Standard Inc in its Central Research Lab, New Jersey. To start the new lab, they invited several prominent scientists like, for example, Professor Anderson who had done some well-known work on structure of silica glass, particularly low temperature acoustic and thermal properties. He joined from the Bell Labs as Manager of Materials and Chemistry Research. I joined the Ceramic and Metallurgy Research Section supervised by G.P.K.Chu, who came from Pfaudler Corp. Professor Anderson had an idea that the Central Lab benefited from being international and he tried it there. He asked Professor Sawai, one of his Japanese friends, to find a new PhD. That was a year before I was completing my PhD, and Professor Sawai transmitted the request to Professor Tashiro, who knew Dr Chu well and recommended me to go there. At American-Standard, I was in a group of scientists from Switzerland, Germany, India and USA. Most of foreign researchers came with an immigrant visa but its quota for Japanese was very few at that times. So, they had to give me a special visa for skilled workers who were lacking in USA. For this purpose, the company put an ad in the Bulletin of the American Ceramic Society to show the Immigration Office that there was no national applicant suitable for the work.

HA: How long did you stay at America- Standard?

NS: I stayed for two years. One of the main topics of our section was glass, because American-Standard makes sanitary products, which require glaze. When they built its Central Lab, the company promised yearly expansion of personnel and budget for a few years, but the company’s profit was low that year and so they could not increase its research budget. Then many good researchers left. Professor Anderson also left there by taking the joint appointment at Bell Labs and the Lamont Geological Observatory of Columbia University, and later he became Professor in its Geology Dept. He started a mineral physics lab at Lamont in order to apply solid-state physics and lattice dynamics to minerals, rocks and the mantle of Earth.

BBV: What was the link with glass science?

NS: They were oxides and silicates, the same components as glass I used to handle. They are polycrystalline materials and so behave isotropic like glass. So, their physical property determination becomes simpler. At Lamont, Professor Anderson set up a project to determine the elastic or seismic waves of model oxide materials under high pressure and high temperature in order to simulate the mantle. He asked me to join there and carry out the experiments as a post-doc, so that I could do some basic research. Since he took me from Japan to do research rather than development, he was quite concerned with my work.

HA: Did you work on fluorescent glasses at American Standard?

NS: Yes, both on glass and crystallized glass, as an applied research for coating. Also worked on manganese systems that could be used like in a kind of fuel cell with oxidation and reduction.

HA: Did you publish this work?

NS: No, but I applied one patent. If you have a proper amount of alkali in germanate, you get fluorescence. There were no data on lithium germanate and so I published a short note on it. American-Standard was interested in coating metal with glass. In order to know whether glass can be coated or not, you have to know the stress and strain at the interface. So I developed a system capable of detecting the strain change with temperature optically. That was patented. Anyway, I was doing some applied research related to glass at American-Standard.

At Lamont, I started to work on crystalline materials, not glass. It required more physics than chemistry. Most of my work were published in geophysical journals. The research experience there was indispensable for me when I came back to Japan and started working again on glass science. For example, the knowledge of lattice dynamics was useful to search new types of glass, such as rare earth-doped photo-hole burning glass. To get multi photo-burnt holes you need to have broad bands, which requires a lot of randomness and disorder in glass. From the vibrational modes, borate glass became a target composition, and this is the reason we worked on borate glasses.

HA To some extent it was a come back to your first subject?

NS Yes. I came back to this subject because glass science was easier for me to get fund and set up a laboratory suitable for making a new approach to glass science.

HA: Let’s go back to the years you spent in American Universities.

NS: I spent three years at Columbia University and then moved to Rice University (Texas). At that time Rice University was trying to expand its Space Science Department by creating a section dealing with planetary interior. I was appointed as its Assistant Professor. In the Apollo Project, a lots of sand and dust were brought back from the Moon, about 50% of which was found to be glassy state. So we had to measure the sound wave velocities of those samples in millimeter size or less than that. We developed a technique to measure them. We used the results as well as those on the rock samples to interpret the propagation of the seismic waves on the moon and discussed its interior.

HA: You came back to Japan in 1970.

NS: In Japan we did not have good equipments so I brought back a self-made system for sound wave velocity measurement in 10 to 60 megahertz. We worked on elastic properties of different types of glasses from the viewpoint of glass structure. We clarified such anomalous behavior in silica-rich (low-alkali) glasses, where a sound velocity decreases under pressure, instead of increasing. For industrial people, elastic properties are important but there are more important properties for practical use of products. This was the reason why we expanded our research to other mechanical properties.

HA: I did a chart displaying all the topics that you covered in your publications. Could you tell us how you moved from one topic to another one?

NS: Perhaps, it looks like moving from one subject to another. However, our research on lattice dynamics and physical properties on inorganic materials - elastic properties, thermal properties, mechanical properties and equation of states - are all related. We always looked them from the viewpoint of glass structure and chemical bond. To understand glass structure more clearly, we made various types of glasses and amorphous materials by different methods, such as rapid quenching, sputtering, sol-gel and so forth, and determined the chemical bonding states and local structure by spectroscopic methods. The study of molecular dynamic simulation of glass structure was also along this line.

BBV: Why did you move to the chemical bond? For industrial reasons?

NS: No it is from scientific reasons. I am a chemist and consider that chemical bond is the basis of composition-structure-property relationship needed for materials design. Also, the molecular dynamic simulation requires an appropriate chemical potential. Bond strength is analogous to spring constant in lattice dynamics, and so we can get information about bond strength by determining spring constants of atomic or ionic vibrations in materials from their thermal and elastic property measurements. Among various materials, we were interested first in silicates, because they are the major constituents of glass and ceramics. Silicates show low sound velocities, although Si-O bond is supposed to be strong. We were concerned about such discrepancy. We considered that it came from the condition of applying the theory of lattice dynamics: that is, it is usually assumed that a solid has close-pack structure and the mass and distance are calculated. This is OK for metals or alkali-halides, but silicates have an open space inside their network. So we borrowed a concept from high polymers and made a model by taking out the space inside of network as a void and putting glass modifiers inside the network. In this model, Si-O network provides its own one-dimensional Si–O vibration mode as well as a low frequency mode by forming large three-dimensional repeated units of SiO2 network similar to the crystal lattice units. The modifiers such as alkali and alkali-earth ions vibrate independently from the Si-O network. We call this the three-band theory and we were able to get the reasonable Si-O bond strength from the low temperature heat capacity measurements. We used this theory to deduce the chemical bond strength not only for other network formers such as B2O3, P2O5 and GeO2 but also for network modifiers.

HA: And you wanted to test this idea in all kinds of glasses, in general?

NS: Yes, glass is an ideal material because you can easily change the composition of network formers and modifiers in large quantity, which is not possible in crystalline state. Therefore, we could get a kind of comparative bond strength for all ions in the periodic table, which agrees well with Born-Mayer potential.

BBV: It strikes me that you developed a kind of materials generic perspective in your study of glass. Was this perspective induced by your studies in geophysics and space science? Or was it that the decade of the 1970s invited such perspective ?

NS: Well, let me put it this way. I regard that it came from working with researchers in different disciplines. You ask me about materials perspective. When I came back in 1970, the dominant approach was still inside of each material, such as ceramics, glass, polymers and so on. Before the 1980s, there was no good textbook of Materials Science in Japan, although there were several books on solid-state chemistry or physics. A professor gave lectures on glass or ceramics by applying thermodynamics, reaction kinetics, phase diagrams and so on. I thought that by introducing lattice dynamics I could expand ceramic or glass science field.

HA: Here you come to my second question: why did you choose glass?

NS: In addition to the above large compositional variations, glass is homogeneous and isotropic so that there are only two independent elastic constants to reduce the interaction between constituent atoms or ions. So, by determining longitudinal and shear wave velocities, one could get the equation of state or connect to thermodynamic properties. If we try to measure them under high pressure and temperature, we can get some detailed information about chemical potential. In case of crystals we need at least 3 independent constants. As crystal structure becomes more complicated, more constants are needed to describe the bulk properties. So glass is an ideal material to study the compositional dependence of pressure-temperature volume relationship for inorganic materials. That is what I thought.

BBV: Did you teach in this general perspective while you were at Kyoto University?

NS: Yes, in the class of inorganic chemistry. At our Department of Industrial Chemistry, we taught Physical Chemistry, Inorganic Chemistry, Organic Chemistry and Analytical Chemistry as the required courses in the junior year and then Inorganic Structural Chemistry, Solid State Chemistry, Electrochemistry, Photochemistry, Organic Structural Chemistry, Organic Synthesis, Nuclear Chemistry, Polymer Chemistry and other subjects as the elective courses in the senior year. I was responsible to teach inorganic chemistry.

BBV There was no attempt at promoting Materials Science as a subject taught at the University?

NS: Not until the 1980s, when we started to combine several chemistry related departments in Faculty of Engineering to one. I was appointed as a professor in 1979, and always thought that we should teach students with a broader view. Professor Kenichi Fukui was awarded the Nobel Prize in theoretical chemistry in 1981 and then a new department called Department of Molecular Engineering was created in his honor. Since it was for graduate students and they needed to have broader knowledge of chemistry, we attempted some change in our undergraduate curriculum, but the complete change was not made until 1993 when five chemistry related departments in the Faculty of Engineering were merged to one School of Industrial Chemistry in the undergraduate level. In Japanese universities, metallic materials are traditionally handled in Department of Metal Science or Engineering and semiconductors are in Department of Electric Engineering. After the 1980s, the department or school of materials science and engineering appeared in many universities, but most of them are renamed from the metal related departments, so that inorganic and organic materials are not well covered in these departments. Consequently, students usually learn material science from the side of chemistry or physics, not from the both sides. It is difficult to regroup the faculty members who are accustomed to traditional teaching disciplines.

HA:Did you try to promote interactions with physicists?

NS: I did it outside of department or university. In the 1990s, there was a movement to create a department of materials science when new universities attempted to have a Faculty of Engineering. For example, the University of Shiga Prefecture where I taught for three years till March 2001, has Department of Materials Science where all students learn metallic, inorganic and organic materials. Unfortunately most of Japanese professors did not have experience in teaching or learning materials Science in general, so they tend to stick to the old approach they learned or taught in the past. .

HA: Did you translate or encourage translations of American textbooks in MSE?

NS: No, but I wrote a book to promote materials science. Although the book is called Elementary Ceramic Science and written for students learning inorganic materials, it follows the approach used in American textbooks in MSE. It is a combination of chemistry and physics, and used as a sub-text not only for inorganic chemistry class but also for other class in metallurgy departments.

 BB: So would you say that the strategy in Japan was to pour new wine in old flasks?

NS: It was the case. Until the end of 1970s, it was the age of recovering and catch-up. The government set up some target area and tried to strengthen its technology. Japanese companies bought patents from abroad and developed them for better products. The national laboratories carried out the task of transferring new technologies to industry, and so the Ministry of International Trade and Industry, MITI, had national laboratories not only in different industrial disciplines but also at 8 locations all over in Japan with some emphasis in local industrial fields: glass in Osaka, ceramics in Nagoya, metals in Tohoku and so on. Then, the Japanese products became high quality and competitive, so that that they were accepted well in the world market and caused friction. Consequently, it became difficult for Japanese companies to get basic technology from abroad. So, the government encouraged the national institutes to shift their emphasis from applied research to basic research in order to build up our own technology. The Science City was planned and built at Tukuba and many governmental laboratories moved from to Tokyo metropolitan area to there, including 7 laboratories under MITI. So, now the majority of researchers of AIST work at Tsukuba.

BBV: The AIST, the National Institute of Advanced Industrial Science and Technology?

NS: Not the new AIST but former AIST, called the Agency of Industrial Science and Technology belonged to MITI. Some of the laboratories in the former AIST has a long history: for example, the Geological Survey of Japan goes back more that 120 years. Fifteen laboratories of the former AIST, particularly those at Tsukuba, devoted themselves to do more fundamental research along the line of seed-oriented governmental projects than applied or developmental research. In January 2001, MITI became METI (Ministry of Economy, Trade and Industry) by taking in the Economic Planning Agency, because of the governmental reform. In April 2001, these 15 laboratories under METI were merged into one independent administrative institute, new AIST, the National Institute of Advanced Industrial Science and Technology.

HA: What is exactly the relation between METI and AIST?

NS: Although AIST is not a governmental institute any more, METI sets the medium-term (four years) research targets, and AIST submits the medium-term plan and gets permission or direction for revision. We are requested to submit the yearly and medium term report to the evaluation committee in METI. This is because we get almost all operating funds from the government and is watched by METI. There are several ministries dealing with science and technology, but now the National Council of Science and Technology Policy under Prime Ministers Office decides the direction and prime areas of research in Japan. As for the materials science, there were other national institutes under the STA ( Science and Technology Agency): NIRIM (National Institute for Research on Inorganic Materials) and NIRIM (National Research Institute of Metals), which were combined to form one independent research organization in Tsukuba.

HA: What is the name of this organization

NS: National Institute of Materials Science (NIMS).

BBV: I found out a page of the National Institute of Materials and Chemical Research. Is it that one?

NS: No, that is one of our former AIST laboratories. NIMS is a different IAI headed by Professor Kishi and doing many researches on nanotechnology. At AIST, we started with 54 research units and now have 62 units with about 2300 permanent researchers, about 250 fixed term researchers and more than 3000 visiting researchers from companies. So it comes up to about 6000 researchers working at AIST. About 1/3 of them are regarded as materials people, more than it shows in the figure in the pamphlet, because many of them work in the units of IT, Environment and Energy.

BBV: Are they all of them paid by the government?

NS: Except those from companies, yes.

HA: What is the difference between research centers and research institutes?

NS: The research institutes are to work on the research requiring continuity and explore R & D seeds based on bottom-up proposals, and the centers are to conduct pioneering & strategic projects with priority in investing research resources, so that they have 5 to 7 years fixed terms. Many of these centers are supported by funds coming from the government for specific projects. For instance the Synergy Materials Research Center, or the Biological Information Research Center, Advanced Semiconductor Research Center, Research Center for Macromolecular Technology and so on. About a half of the directors of these centers came from industry and university, who are well known in the respective field.

HA: Do scientists easily move from an institute to a research centers?

NS: That is a problem. At AIST, we keep our status as government employee, and when AIST started, it was agreed that each researcher has the right to choose his or her research unit. So, in order to move him or her from one unit to another, we need to have the agreement of individual researcher.

HA: It is like the French CNRS.

NS: I understand that when CNRS decided to move a Glass Science Laboratory from Paris to Montpellier they could do so by moving researchers and hiring new ones. Here we had to keep all the people and directors or project leaders have difficulty in getting suitable researchers, because researchers tend to keep their ongoing work, not to change the subject unless they recognize the dead end by themselves. This problem is not only at AIST but also everywhere in Japan. Coming back to the case of materials science, the shift from one research discipline to another is still not easy because they are trained in one area of materials. If a company wants to build up a glass group, they go to a university and try to hire a student working in the glass laboratory. The same situation applies to electronic engineers. So the professors who care for the employment of average students tend to give training in traditional manner. In Japan, as I said before, many metallurgy departments changed their name to Materials Science.

BBV When did they change their name?

NS: Starting from the early 1990s when leading national universities went to emphasize their graduate education. During the 1960s, the Japanese Ministry of Education expanded national universities, particularly their faculty of engineering to send out undergraduates to support industry. Not so many undergraduates went to graduate school. Then in the 1970s and 1980s, emphasis was placed on masters programs in graduate school in order to answer the industrial demands for more qualified researchers and engineers. Most of undergraduate students went into the masters programs for getting better employment rather than pursuing Ph D. The reason is that in Ph D courses students usually do research in a specific field to make Ph D thesis, although industry likes to have researchers who can attack different projects according to their needs. In the 1990s, Japan faced national and international demands for innovation of science and technology. The government requests universities to accept more graduate students, particularly in Ph D course, and put more emphasis on course works to give students more general knowledge attractive to industry. It was in this context that many metallurgy departments were renamed as departments of materials science.

BBV: So it is quite recent.

NS: Very recent, in the 1990s. The graduate course of Department of Industrial Chemistry was also renamed Department of Materials Chemistry covering inorganic and organic materials but not metallic or semiconductor materials. The undergraduate course was still keep the old name, School of Industrial Chemistry and emphasis is on chemistry.

BBV: Do you think that the Materials Departments are more attractive for students than more traditional departments.

NS: I am not sure. The demand for engineers in Japan is going down, and in general the number of students interested in science and technology are down also. Renaming the department usually does not make a change in professors.

HA: What about the nanotechnology program.

NS: The nanotechnology programs are being carried out at various national laboratories and universities. In the national level, nanotechnology program is one of the four prime areas with life science, environment and information technology, which were set by the National Council for Science and Technology Policy.

BBV: This list of priorities seems to suggest that materials are no longer a priority.

N: Nanotechnology is closely related to materials research and so it is gaining more importance. At AIST, more than a half of research units were working on nanotechnology, although the names of research units do not show it clearly. If you get them working together by moving personnel, for example from Osaka to Tsukuba, we would advance materials research more.

BBV: What kind of incentive could you use to manage such contacts or coordination? Money? Equipement?

NS: We already have given reasonable amount of money and equipments. But you know researchers! They move from AIST to universities although their salaries will be cut by 30%, because they prefer to have the liberty of choosing their research topics. They can have their own castles at universities and above all they can contact with the young students. Compared to the number of professors and researchers in Japan universities (about 300 000), we are small in number. So what is the role of the research institutes at AIST? Probably we have to act as go-between, or mediators between universities and industries.

BBV: To what extent industry was the driving force in the recent changes in national science policy?

NS: Because of recession in economy, industry has a little resource for basic research now and so they support the national science policy, hoping to get new innovative technology. Researchers at AIST as well as those in universities are now trying not only to publish papers but also to apply patents.

BBV: Publishing or patenting what is the most rewarding for a university researcher in this country?

NS: Publishing in journals such as Nature or Science is more prestigious like everywhere in the world. This is not a very favorable situation for materials researchers compared with to those working in life science. Not so many papers on titanium oxide or a catalyzer are found in Science or Nature. Impact factors in professional journals of Metals or Ceramics is very low, although high temperature superconductors can still find their way in Science.

BBV: You have spent 8 years in the USA and since then you have traveled a lot aborad. Did you notice any difference in the style of research or academic life?

NS: In the USA it was always competitive. In Japan we are more relaxed. My son is now teaching at Cambridge, UK, after his getting PhD at Berkeley. His working style is in between USA and Japan. I have an impression that in Europe it is academic recognition that matters, in the USA it is money, and here in Japan it is probably social status.

BBV: What are the indicators of your social status?

NS: The institution you belong to. Professorship at a prestigious university, like University of Tokyo and Kyoto University, or employee of big famous companies such as Hitachi or NEC. It is a tacit hierarchy.

BBV: It does not encourage venture business

NS: Yes, venture business is quite difficult in Japan. People here seem to select security more than adventure.

BBV: Coming back to you. At this point of your long career do you consider yourself as a materials scientist or as a glass scientist.

NS: Probably as an inorganic materials scientist. In order to bridge between basic research and applied research or development, we need some basis of consideration or background, not just the knowledge of a specialized field. Like chemistry in the past, I think that Materials Science will open many opportunities in different fields such as biotechnologies, nanotechnology and so on. Materials Science becomes a sort of basic knowledge for researchers who have to deal with any material. It is the scientific basis for making and using materials.

HA: Do you consider yourself as working in basic science or applied science? It seems to me that you continuously moved from basic to applied science and fundamental again

NS: Well, I do not distinguish applied science from basic science. I came back to Japan because I wanted to teach students how to attack new problems based on basic science. Moving from lattice dynamics to applications was an actual example for them. The object I took in Japan has been glass because of my institutional affiliation.

BBV: When you taught at Kyoto University did you have the feeling that you were importing American culture?

NS: Yes. By living for 8 years in the USA after finishing Ph D without working in Japan, American culture or the way to approach research stays inside me. My friends sometimes say that my behavior is not of a pure Japanese. This may be helping me to get into the international matters. My aim has always been to educate young people with an international way of thinking, and to help them to become top researchers internationally. When senior students came to my laboratory and could not find any theme by themselves after 2 years, I became directive and assigned them to work on mechanical properties so that they could study solid-state physics.

HA: How do you see the future of Materials Research?

NS: In the combination of materials, hybrids, sol-gels among others. Glass can be made not only by melting processing, but also by sputtering deposition or by sol-gel process. The properties of glassy products probably depend on the process used to make it. In the nano-scale level, structure should be slightly different. How much different? We don’t know. The medium range order should be different. That is the reason why we studied various glass preparation processes.

HA: Is that the main reason why you studied glass thin films?

NS: Yes. I was curious of the way structure was stabilized in the amorphous state. The glass forming region of any system becomes wider by making thin films. Can it induce different nanoscale structures?. Maybe SiO2 nanocages could interconnect and act like carbon nanotubes? Its structure and properties may change depending on the process. Is it possible to make epitaxial amorphous films with controlled directional property?

HA: What kind of contacts did you have with industrial companies?

NS: I had some contacts with companies, and they tried to develop products based on our finding. For example, oxynitride glass. It was patented and developed by Shimadzu Co. Its properties were quite good and it was possible to draw fibers of these glasses. However, no direct application field was found and the project was abandoned. Porous glass Professor Nakanishi and I worked on is going on with Merck Co., is now marketed as a new type of capillary columns.

HA: Even on the form of thin films?

NS: Regarding thin films, we did not do any industrially oriented research.

HA: Where the idea of working on magnetic properties came from?

NS: In my laboratory, students sometimes worked on iron-containing glass. Dr. Tanaka expanded that work extensively. He wanted to work on the subjects not covered by other groups. Also, I found attractive to the idea for transparent magnetic glass.

HA: This gave you the possibility to understand coordination number of iron.

NS: Yes, the coordination number of transition elements such as iron governs the optical properties. But optical characterization methods cannot detect local environment. Therefore, it was attempted to probe local structure by using ESR (electron spin resonance) and Mossbauer spectroscopy. Understanding what is the local state of chemical elements - iron, manganese, rare-earth elements - in glass was along our main objective of studying glass structure. I found important that students take into account the chemical bonding states of these elements and correlate local structure with bonding state.

HA: This is to some extent what Professor Hirao is doing.

NS: Yes, he opened a new field. I regard myself as a chemist and admire physics and tried to incorporate it in my study. When I went to the USA first time, some one gave me a card with a mention "physicist" on it. I would never have thought to use a card with "chemist" on it. Physics is highly regarded in the Japanese society.

BBV: You mean that chemistry is low ranking

NS: Yes, compared to physics and mathematics, particularly these days because chemistry is somehow branded as the villain for environmental problems, forgetting the benefits chemistry gives daily life.

BBV: So you are also under the influence of the positivist hierarchy of science. But tell us about the place of glass within materials science. Is it more prestigious, more valued, than semiconductors, carbon or polymer science?

NS: Probably people here do not think of glass as a scientific subject to study. Glass has been looked from technological viewpoint.

HA: Are ceramics and glass always associated in this country?

NS: Yes for historical reasons. Glass is a part of ceramics, glass being used for coating on pottery.

BBV: Is glass more attractive for students than more advanced materials?

NS: Optical fibers popularized glass as an advanced material, but I am not sure whether glass is less attractive then other advanced materials. As I said before, the image of materials in society is low in Japan. There is a concern in the Chemical Society of Japan and in the Ceramics Society of Japan to change this image. People are enjoying materials as a means for an end, but many materials are not considered as environmentally friendly materials. So we have to change people’s mind in the same way as we need for atomic energy. This is the dilemma of materials in this society: common people want to enjoy material products but they are against the production of materials.

BBV: You mean that there is a growing concern with the public acceptance of materials? Are you aiming at more environment-friendly materials in this country?

NS: This is a society problem. We are not willing to pay extra money for them. Actions made by the government and by individuals are completely separated. This is one of the dangers of the Japanese society.

BBV: You started pointing out the problems concerning materials in this country. Could you go ahead and point out other weaknesses and symmetrically what you consider as the strengths of Japan?

NS: Our society does not consist of mixed race. We keep a policy of limiting immigrants. The similar kind of discrimination exists in gender discrimination. Japanese people are still homogeneous which influence people’s thinking. We need more heterogeneity in many respects. More mixing of scientific disciplines and of people are needed. Most of the graduate students come from the same universities. They tend to devote themselves to a specific subject under their professors’ guidance. This may be regarded as a weakness of Japanese science because they tend to go deeper and deeper in only one area, but I think that this tendency turns to be the strength of Japanese science if they are given a chance to get together with researchers in other fields.

Two years ago, I was asked to be a research mentor for PRESTO Program in materials field by Japan Science and Technology Corporation. This program aims at cultivating the seeds of precursory science and technology by promoting basic research in which the originality of individual researchers can be fully realized. In one field, about ten young researchers are selected each year for the period of 3 years with direct research budget of about 40 million yen per researcher. The program runs for three years, so that about 30 young researchers have chance to get together and discuss their projects with others. Taking this opportunity, I decided to try mixing of young researchers from different disciplines in materials science by setting the research area "Structural Ordering and Physical Properties", which focuses on the clarification of fundamental correlation between structural ordering/disordering and physical properties of materials arising from their low dimensional, amorphous, hybrid or other unusual state. This is what I had been doing in inorganic materials and wanted to expand it to all kinds of materials. There were a lots of applications from metallic, inorganic, organic and composite materials fields, and I was able to select very bright researchers from different universities and institutions in various fields. I hope that through this program they will widen their view for future research and strengthen materials research even though they could not reach the final goal of their own project during three years of time.

The second problem is language. All the textbooks are written in Japanese. English becomes the international language, but only few courses are taught in English. Although e-mail and other means of communication are getting popular, face-to-face contact and discussion among researchers are becoming more and more important to international cooperation. At the present level of English Japanese people will be left behind from the international scientific society. In order to improve the situation, I request participants of the above program to present and discuss their results in English at our gathering. Japan has been contributing the progress of materials science in the past. I hope that Japan continues to do so by promoting internationalization in many respects.

Thank you very much for your interviewing me.

This page was last updated on 29 January 2003 by Arne Hessenbruch.