Pusan National University professor Jeong Se-youngs research team identified the cause of copper oxidation for the first time in the world
Copper Oxidation Schematic Model
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Reporter Jeong Yun-ju = A Korean research team has proven the theory that copper, which oxidizes and changes color when exposed to air for a long time, is not oxidized when made into a thin film with a height of a monoatomic layer.
The Ministry of Science and ICT announced on the 17th that a research team led by Pusan National University Professor Jeong Se-young, Sungkyunkwan University Professor Kim Young-min, and Mississippi State University Professor Kim Seong-gon discovered the worlds first copper oxidation principle using a self-developed ultra-flat copper thin film.
Copper, which has a reddish-brown color, turns blue-green when oxidized. The Statue of Liberty in the United States was also reddish-brown at the time of its establishment, but due to the nature of the copper alloy statue, it is now turquoise after a long time.
The research team conducted an experiment exposing a self-developed ultra-smooth copper thin film with the level of monoatomic layer roughness to the air for one year.
When the thin film was observed using a high-resolution transmission electron microscope, copper was not oxidized.
This is because the thin film used by the research team is very thin with an atomic layer at the level of one layer during development.
When the surface roughness of the thin film is two or more atomic layers, oxygen easily penetrates into the copper. However, if the thin film is perfectly flat or has a monoatomic layer, oxidation does not occur at room temperature because very large energy is required for oxygen penetration.
The research team also discovered that the oxygen present on the surface of the ultra-smooth thin film has a self-regulating function that suppresses oxidation by pushing out other oxygen when 50% of the space where oxygen can exist is full.
The research team said that they have provided an opportunity to replace gold used in nano circuits with copper thin films by revealing the cause of copper oxidation.
Professor Jeong said that this research result is the first case in the world to identify the origin of copper oxidation at the atomic level, and opens up the possibility of manufacturing unchanging copper.
The results of this study were published in the international scientific journal Nature.