On Monday, March 10, 2025, the "53rd Research and Education Center for Natural Sciences Lecture (2024 Young Researcher Award Lecture) Freely Manipulating the 'Structure' of Solid Materials: In-situ Control of Crystal Structure via Stimuli" will be held.

Our prosperous lives are supported by various materials (pharmaceuticals, building materials, semiconductors). In fact, most materials are substances called crystals, which are solids in which atoms and molecules are arranged in a periodic and orderly manner. The performance of a material depends significantly not only on the types of atoms and molecules that compose it but also on their arrangement. On the other hand, crystals are stable solids, and it has been extremely difficult to change the molecular arrangement while maintaining the crystalline state to switch the material's performance.

In this research, we succeeded in controlling the structure and physical properties of crystals using external stimuli such as heating and vapor exposure, employing photochromic crystals that change color when exposed to light. Organic crystals of salicylideneaniline ammonium salt (SA) are known to exhibit color changes due to light when the shape of the molecules contained in the crystal is non-planar. I succeeded in switching the photoresponsivity of SA by changing the planarity of the molecules in the crystal, utilizing the adsorption and desorption of ammonia molecules through exposure to ammonia vapor and heating stimuli.

Currently, ammonia is attracting attention as an energy source and a hydrogen carrier molecule. Since the structure and physical properties can be controlled using the adsorption and desorption of ammonia molecules, the use of SA can be expanded to various fields, including industrial applications such as ammonia sensors.

In this presentation, I will also briefly introduce the Japan Proton Accelerator Research Complex (J-PARC), where I am currently affiliated, including the state of experiments using neutron beams and how they are utilized in research.

【Date and Time】

Monday, March 10, 2025, 13:00–14:30

【Venue】

Hiyoshi Campus, Raiosha 1st Floor, Symposium Space

【Target Audience】

Students, Faculty/Staff, General Public

【Advance Registration】

Required (On-site registration also available)

*Click here for advance registration.

【Fee】

Free

【Organizer】

Keio University Research and Education Center for Natural Sciences

【Contact Information】

Keio University Research and Education Center for Natural Sciences Secretariat (Inside Raiosha, Hiyoshi Campus)

4-1-1 Hiyoshi, Kohoku-ku, Yokohama 223-8521

office[at]sci.keio.ac.jp

Please see here for details regarding registration and other information.