Day14: Jun Akimitsu

The reason: The advanced material scientist

Among the visionaries I wrote here, he is special to me because he is (was?) my teacher. He supervised my Ph.D. He is not only good scientist but also good educator. Maybe, I am taking huge risk by writing this here. But, I write anyways.

I don’t need to mention, how he have been awarded many prizes in Japan including Asahi prize, Nishina memorial prize, and the Order of the Sacred Treasure Gold Rays with Neck Ribbon. I believe (maybe I will get a lot of criticism) there are huge contributions to science from him. I am a professional scientist but I cannot write seriously here. So, you should not use this information as a source.

• As an instrument scientist

After getting Ph.D. from Univ. of Tokyo, he had worked for ISSP (Institute of solid state physics: Univ. of Tokyo) as instrument scientist. Some of readers here might know I am going to be an instrument scientist too. I could learn a lot from him. He has many collaborators now to pursuit his science because He helped a lot of scientist to do experiment when he was an instrumental scientist. However the great thing is it is said that he said “you don’t need to put my name on your paper”. So many scientists who was helped by him says “I owed Akimitsu-san a lot” now.

• Superconductivity

He and his group are famous for searching new superconductor. Superconductivity is a phenomenon the material shows absolutely zero resistivity and exclusion of magnetic field under certain critical temperature. There is huge possibilities for application though, since the temperature is very low (typically around absolute zero temperature), the most important goal for experimental researchers are finding new superconducting material which shows superconductivity at high temperature. One of great achievement of his group is finding MgB2, which have highest critical temperature among metallic compound. Metallic superconducting material is important because it is very easy to process.

• Orbital ordering

There are three of degrees of freedom which are charge, spin, and orbital in material. The charge and spin can order when the system overcome thermal energy by cooling the system. Also the orbital could order in material. Material scientists have been finding that the orbital ordering can be very important to know the physical properties of the material. Basically, there are two experimental methods to observe the orbital order in material. One is the polarized neutron scattering technique and the other is resonant X-ray scattering techniques. Prof. Akimitsu had done one of earliest example of the polarized neutron scattering experiment in 1976. Next example I know is from Dr. Ichikawa. He had used this technique for observing orbital order in YTiO3 in 2001. This is also important achievement in material science though, that also had shown how Prof. Akimitsu’s technique advanced. And unfortunately, as far as I know, there is no group can use this technique today.

• Multiferroics

Multiferroics defined as materials the exhibit more than one ferroic order parameter simultaneously.  The phenomenon is not so new but scientists now started to understand the mechanism of origin of multiferroic property from the microscopic point of view. For the application, the point is that we could control its physical properties by external field in different way. Usually, if we want to control the magnetic properties, we need to use magnetic field and if we want to control electric properties, it need to be control by electric field. But, mutiferroics can be used in different way. For example, the magnetic properties of material could be control by electric field and vice versa. In 2007, some group published the paper that proves this phenomenon by using the polarized neutron scattering technique under the electric field. Prof. Akimitsu had done similar experiment in 1978 already.

To be honest, I am kind of shy to write here. And unfortunately, I don’t have good English proficiency enough to describe very well. I am sorry.