Development of wavelength-dispersive depth-resolved X-ray absorption spectroscopy and real-time observation of reactions in perpendicular direction of films

2020 Fiscal Year Final Research Report

• Project/Area Number: 19K22091
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 27:Chemical engineering and related fields
• Research Institution: High Energy Accelerator Research Organization
• Principal Investigator: Amemiya Kenta 大学共同利用機関法人高エネルギー加速器研究機構, 物質構造科学研究所, 教授 (80313196)
• Project Period (FY): 2019-06-28 – 2021-03-31
• Keywords: 軟X線吸収分光 / 深さ分解 / 波長分散型 / リアルタイム観察 / 化学反応

Outline of Final Research Achievements

We have developed a new technique for non-destructive real-time observation of chemical reactions progressing in depth using X-ray absorption spectroscopy (XAFS) in the soft X-ray region. By irradiating the sample surface with wavelength-dispersed soft X-rays (with different wavelengths depending on the position) and imaging the fluorescence X-rays, whose intensity is proportional to amount of soft X-ray absorption at each position, using two spherical mirrors, as well as by discriminating the emission angle of the fluorescence X-rays, we have simultaneously achieved a time resolution of the order of seconds and a depth resolution of better than nm.

Free Research Field

表面科学

Academic Significance and Societal Importance of the Research Achievements

本研究は軟X線吸収分光を用いた化学反応の観察において，秒レベルの時間分解とnmを切る深さ分解を同時に実現したものである。触媒表面で起こる反応，薄膜型二次電池の充放電過程，電極表面における電気化学反応など，深さ方向に進行する反応は数多くあるが，そういった反応を実際の反応に近い条件で，実際に反応が起こっている時間スケールと深さスケールで観察することは，反応の仕組みを理解するのに大きく役立ち，反応の効率や速度を向上させることにつながる。