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[표지로 읽는 과학] X-Ray Great Leap, Single Atom Capture : Dong-A Science

The international journal ‘Nature’ featured enlarged atoms on its cover this week. Above the somewhat blurry image showing various atomic arrangements, a large ‘ATOMIC POWER’ clause is inserted. Under this phrase, the phrase ‘X-ray simultaneously holds the elemental and chemical properties of a single atom’ was placed.

The discovery of X-rays had a profound effect on the medical and other scientific fields. The German physicist Wilhelm Roentgen, who was studying gas emission phenomena, accidentally discovered X-rays in 1895, and was awarded the first Nobel Prize in Physics for this accidental discovery.

Professor Sowai Hla’s research team from Ohio University captured an atom via X-rays for the first time in history and published research results in Nature on the 31st (local time). An atom is the smallest structural unit that makes up a substance, and it is also the smallest unit that has the chemical properties of an element that is fundamental to the composition of matter.

Meanwhile, X-rays have been used to identify properties of materials that cannot be seen with the naked eye. The X-ray signal produced by atoms is very weak, which makes it difficult to photograph single atoms with ordinary X-rays. Synchrotron X-rays were developed to reduce the amount of samples needed for X-ray imaging, but the smallest atomic weight of X-ray imageable material was greater than 10,000.

The research team managed to capture a single atom with specially designed synchrotron X-ray equipment. The device was purpose-built at the XTIP beamline of the Center for Advanced Photon Sources and Nanomaterials at Argonne National Laboratory, USA. A beamline is a device that selects radiation of the desired energy only when electrons rotate and emit radiation. The XTIP beamline is the world’s first dedicated beamline for synchrotron X-ray scanning tunneling microscopes.

The research team created a synchrotron X-ray scanning tunneling microscope (SX-STM) that can be placed very close to the sample to take a picture of it by attaching a sharp metal needle to an existing X-ray detector. Through this, the research team was able to take an X-ray image of one iron atom (Fe) and one terbium atom (Tb).

Professor Hla, who led the study, said, “Although atoms can be visualized with special microscopy equipment, it is impossible to know what they are made of without using X-rays.” “It is now possible to measure the chemical state of these. atoms at the same time.”