2023-05-31 オハイオ大学
◆この技術により、材料の種類や化学状態を1つの原子単位で同時に測定することができます。この発見は環境科学や医学科学に大きな影響を与え、新たな治療法の開発にもつながる可能性があります。
＜関連情報＞
- https://www.ohio.edu/news/2023/05/scientists-report-worlds-first-x-ray-single-atom-nature
- https://www.nature.com/articles/s41586-023-06011-w
放射光X線による原子1個の特性解析に成功 Characterization of just one atom using synchrotron X-rays
Tolulope M. Ajayi,Nozomi Shirato,Tomas Rojas,Sarah Wieghold,Xinyue Cheng,Kyaw Zin Latt,Daniel J. Trainer,Naveen K. Dandu,Yiming Li,Sineth Premarathna,Sanjoy Sarkar,Daniel Rosenmann,Yuzi Liu,Nathalie Kyritsakas,Shaoze Wang,Eric Masson,Volker Rose,Xiaopeng Li,Anh T. Ngo & Saw-Wai Hla
Nature Published:31 May 2023
DOI:https://doi.org/10.1038/s41586-023-06011-w
Abstract
Since the discovery of X-rays by Roentgen in 1895, its use has been ubiquitous, from medical and environmental applications to materials sciences. X-ray characterization requires a large number of atoms and reducing the material quantity is a long-standing goal. Here we show that X-rays can be used to characterize the elemental and chemical state of just one atom. Using a specialized tip as a detector, X-ray-excited currents generated from an iron and a terbium atom coordinated to organic ligands are detected. The fingerprints of a single atom, the L2,3 and M4,5 absorption edge signals for iron and terbium, respectively, are clearly observed in the X-ray absorption spectra. The chemical states of these atoms are characterized by means of near-edge X-ray absorption signals, in which X-ray-excited resonance tunnelling (X-ERT) is dominant for the iron atom. The X-ray signal can be sensed only when the tip is located directly above the atom in extreme proximity, which confirms atomically localized detection in the tunnelling regime. Our work connects synchrotron X-rays with a quantum tunnelling process and opens future X-rays experiments for simultaneous characterizations of elemental and chemical properties of materials at the ultimate single-atom limit.
