Scientists report in Nature the first X-ray of an atom using X-rays
A team of scientists from different universities and institutions in the United States obtained the first X-ray image of a single atom. This groundbreaking achievement could revolutionize the way scientists detect materials.
Since their discovery by Roentgen in 1895, X-rays have been used everywhere from medical exams to airport security checks. Even Curiosity, NASA’s Mars rover, is equipped with an X-ray device to examine the material composition of rocks on Mars. An important use of X-rays in science is to identify the type of material in a sample.
Over the years, the amount of material in a sample needed for X-ray detection has been greatly reduced by the development of synchrotron X-ray sources and new instruments. To date, the smallest amount that can be radiographed from a sample is in attograms, i.e. about 10,000 atoms or more. This is because the X-ray signal produced by an atom is extremely weak, so conventional X-ray detectors cannot be used to detect it. According to Hla, it is an old dream of scientists to X-ray a single atom, which is now being realized by the research team led by him.
“Atoms can be seen routinely with sounding scanning microscopes, but without X-rays you can’t tell what they are made of. Now we can detect exactly the type of a given atom, one by one, and simultaneously measure its chemical state,” explained Hla, who is also director of the Institute for Quantum and Nanoscale Phenomena at Ohio University. “Once we can do that, we’ll be able to trace materials down to the maximum limit of a single atom. This will have a huge impact on medical and environmental sciences and we may even find a cure that could have a huge impact on humanity. This discovery will transform the world.”
your article, published in the scientific journal Nature details how Hla and several other physicists and chemists used a synchrotron X-ray instrument built specifically on the XTIP beamline of the Advanced Photon Source and Nanoscale Materials Center at Argonne National Laboratory.
For the demonstration, the team chose an iron atom and a terbium atom, both inserted into their respective molecular hosts. To detect the X-ray signal from one of the atoms, the research team supplemented conventional X-ray detectors with a specialized detector consisting of a sharp metal tip placed in extreme proximity to the sample to collect the electrons excited by the atoms. rays. X, a technique known as scanning synchrotron X-ray tunneling microscopy, or SX-STM. The X-ray spectroscopy in the SX-STM is activated by the photoabsorption of central level electrons, which constitute elemental fingerprints and are effective in directly identifying the elemental type of materials.
According to Hla, spectra are like fingerprints, each one unique and capable of detecting exactly what it is.
“The technique used and the concept demonstrated in this study break new ground in X-ray science and nanoscale studies,” says Tolulope Michael Ajayi, first author of the paper and doing this work as part of his doctoral thesis. “In addition, the use of X-rays to detect and characterize individual atoms could revolutionize research and give rise to new technologies in areas such as quantum information and detection of trace elements in medical and environmental research, to name a few. This achievement also paves the way for advanced instrumentation in materials science.”
For the past 12 years, Hla has been involved in the development of an SX-STM instrument and its measurement methods with Volker Rose, a scientist at Argonne National Laboratory’s Advanced Photon Source.
“I was able to successfully supervise four OHIO graduate students in their doctoral theses related to the development of the SX-STM method over a period of 12 years. We’ve come a long way to achieve detection of the X-ray signature of a single atom,” said Hla.
Hla’s study focuses on nanometric and quantum sciences, with particular emphasis on understanding the chemical and physical properties of materials at the fundamental level, ie the level of the individual atom. In addition to obtaining an atom’s X-ray signature, the team’s main goal was to use this technique to investigate the environmental effect on a single rare earth atom.
“We also detect the chemical states of individual atoms,” explained Hla. “By comparing the chemical states of an iron and a terbium atom within their respective molecular hosts, we find that the terbium atom, a rare earth metal, is quite isolated and does not change its chemical state, while iron strongly interacts with its environment.
Many rare earth materials are used in everyday gadgets such as cell phones, computers and televisions to name a few and are extremely important in the creation and advancement of technology. Thanks to this discovery, scientists can now identify not only the type of element but also its chemical state, allowing them to better manipulate atoms in different host materials to meet ever-changing needs in various fields. In addition, they also developed a new method called “X-ray excited tunneling resonance or X-ERT”, which allows detecting how the orbitals of a single molecule are oriented on the surface of a material using synchrotron X-rays.
“This achievement connects synchrotron X-rays with the quantum tunneling process to detect the X-ray signature of an individual atom and opens up many exciting avenues of research, including investigation of the quantum and spin (magnetic) properties of a single atom. ”. atom using synchrotron X-rays,” said Hla.
Moving forward, Hla and her research team will continue to use X-rays to detect properties of a single atom and find ways to further revolutionize its applications for use in research for critical materials for collection and beyond.
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