RESEARCH

Our research aims to create innovative functional inorganic materials through curiosity-driven exploratory synthesis and rational elucidation of the synthesis-structure-property relationship. Through cutting-edge research, we provide a unique learning opportunity for students and young researchers, equipping them with professional skills and fostering international communication.

1) Curiosity-driven exploration of non-oxide materials with exciting properties

The discovery of novel structures driven by curiosity-based exploration is essential for the advancement of chemistry. By combining a variety of elements from the periodic table, we can create new structures with exciting properties. We mainly focus on non-oxide compounds with different anions, such as N³⁻, NCN²⁻, and Cl⁻. Nitride anion (N³⁻) is a trivalent one with a similar ionic radius with divalent oxide anion (O²⁻), and various properties arise with different local and average structures, emerging ferroelectric or electrocatalytic applications. The valence of NCN²⁻ is the same as that of O²⁻, but this molecular anion with a bar shapes show unique thermal- or pressure-dependent luminescence properties. Cl⁻ is a larger and softer ion, which brings unique mechanical properties and excellent ion transport that is important for energy applications, such as all-solid-state batteries. We also focus on novel synthesis method for producing new compounds and structural analysis of synthesized materials, which clarifies the structure-property relationship.

1. Stress-Induced Martensitic Transformation in Na3YCl6 
   Journal of the American Chemical Society, 146(36) 25263-25269, Sep 2024
2. Average Cubic BaTaO₂N Crystal Structure Formed by 50 nm Size Domains with Polar Nanoregions Consisting of cis-TaO₄N₂ Octahedral Chains 
   Chemistry of Materials  36, 15, 7504–7513, Jul 2024 
3. High-pressure behavior of tetragonal barium carbodiimide, BaNCN
   Journal of Alloys and Compounds 918 Oct 2022

2) Elucidation of the synthesis-structure-property relationship toward efficient synthesis

The exploration of inorganic compounds synthesized to date has required considerable effort and time. In the search for next-generation materials, more efficient methods are in demand. Computational science can estimate the thermodynamic driving force from reactants to products, but predicting the synthesis pathways of target substances remains challenging since products are formed through processes involving long-range diffusion and nucleation to form specific crystals. Therefore, to design material synthesis efficiently and rationally, it is crucial to understand synthesis methods through both thermodynamics and kinetics. In-situ synchrotron XRD and in-situ electron microscopy observations are powerful tools for understanding synthesis methods, as they allow us to observe reaction processes during heating. By combining synthesis experiments, computational science, and in-situ analysis, we aim to develop innovative new materials efficiently through a rational understanding of synthesis reactions.

1. The Detail Matters: Unveiling Overlooked Parameters in the Mechanochemical Synthesis of Solid Electrolytes
   ACS Energy Letters 156-160 2025
2. Observing and Modeling the Sequential Pairwise Reactions that Drive Solid-State Ceramic Synthesis
   Advanced Materials 2100312-2100312 2021年5月5日
   https://youtu.be/2DknN3zJco4

3) Collaborative research (university, industry)

We have collaborated with various domestic and international universities and companies. We have strong collaborations for synchrotron and neutron analysis of detailed average and local structures and understanding reaction mechanism. We intensively collaborate with computational teams to understand synthesis and property insights from structure and energy analysis.

1. Efficient Exploratory Synthesis of Quaternary Cesium Chlorides Guided by In Silico Predictions
   Journal of the American Chemical Society, 146(43) 29637-29644, Oct 16, 2024
   Science Japan(10.22.2024)
   The Atlantic: Dialogues