Rapid etching X-rayed: Physicists unveil processes during fast chemical dissolution

Mar 23, 2011
Graphical representation of the experiment. The X-ray beam impinges on a gold surface, which is chemically dissolving. A fast X-ray detector captures the reflected beam. From the fluctuations of the beam intensity with time, the atomic-scale changes at the surface are deduced. Copyright: CAU, artwork: J. Golks

A breakthrough in the study of chemical reactions during etching and coating of materials was achieved by a research group headed by Kiel physicist, Professor Olaf Magnussen. The team from the Christian-Albrechts-Universitat zu Kiel (CAU), Germany, in collaboration with staff from the European Synchrotron Radiation Facility (ESRF) in Grenoble, France, have uncovered for the first time just what happens in manufacturing processes, used for the formation of metal contacts thinner than a human hair in modern consumer electronics, such as flat-screen television. The results appear as the cover feature in the current issue of the renowned Journal of the American Chemical Society.

For their research the scientists used the intense X-ray radiation of the experimental station ID32, one of the ESRF's instruments. The X-ray beam was directed onto a while it dissolved in diluted hydrochloric acid. Because the reflected are sensitive to tiny changes in the atomic arrangement at the material's surface, the metal removal during the reaction can be precisely measured. "Such studies were only possible during very slow changes of the material so far", Olaf Magnussen explains. To gain insight into the fast reactions going on in industrially employed processes the speed of the measurements had to be increased more than a hundredfold. Even during very fast etching the removal of the metal proceeded very uniformly. "The material dissolves quasi atomic layer by , without formation of deeper holes", Magnussen remarks. In a similar way, the team could follow the attachment of atoms during the chemical coating of materials.

Among the diverse industrial applications of chemical etching and coating are high-tech manufacturing processes, for example in the production of electronic devices. These require precisely controlled reactions. In order to optimize such etching and coating processes they are intensely studied worldwide. Until now it was only possible to analyse the finished product. With the method developed by the scientists, changes within a few thousandth seconds may be detected so that the reactions at the material's surface can be tracked on the atomic scale under realistic conditions.

Christian-Albrechts-Universität zu Kiel is a North German research university with proven international expertise in the field of nanoscience, including research using synchrotron radiation. In a number of research networks, funded by the German Federal Ministry of Education and Research, Kiel scientists develop new methods and instruments. In addition, the CAU competes for a Cluster of Excellence in the area of nanoscience and surface science within the ongoing round of the German Excellence Initiative.

Explore further: Pseudoparticles travel through photoactive material

More information: F. Golks, K. Krug, Y. Gründer, J. Zegenhagen, J. Stettner, O. Magnussen: High-speed in situ surface X-ray diffraction studies of the electrochemical dissolution of Au(001). Journal of the American Chemical Society 2010, 133, 3772

Related Stories

The nanoworld of corrosion

Feb 09, 2006

The effect of corrosion has an impact on about 3% of the world's Gross Domestic Product. From a positive point of view, however, chemical attack of metal surfaces may result into surface nano-structures with ...

Discovery of an anti-inflammatory substance

Nov 08, 2010

The messenger interleukin-27 plays an important role when the human body blocks inflammations. This was discovered by an international research team, of which the Kiel Professors Joachim Grotzinger and Stefan Rose-John, as ...

Living longer thanks to the 'longevity gene'

Feb 03, 2009

A variation in the gene FOXO3A has a positive effect on the life expectancy of humans, and is found much more often in people living to 100 and beyond - moreover, this appears to be true worldwide. A research group in the ...

Recommended for you

Pseudoparticles travel through photoactive material

Apr 23, 2015

Researchers of Karlsruhe Institute of Technology (KIT) have unveiled an important step in the conversion of light into storable energy: Together with scientists of the Fritz Haber Institute in Berlin and ...

From metal to insulator and back again

Apr 22, 2015

New work from Carnegie's Russell Hemley and Ivan Naumov hones in on the physics underlying the recently discovered fact that some metals stop being metallic under pressure. Their work is published in Physical Re ...

Electron spin brings order to high entropy alloys

Apr 22, 2015

Researchers from North Carolina State University have discovered that electron spin brings a previously unknown degree of order to the high entropy alloy nickel iron chromium cobalt (NiFeCrCo) - and may play ...

Expanding the reach of metallic glass

Apr 22, 2015

Metallic glass, a class of materials that offers both pliability and strength, is poised for a friendly takeover of the chemical landscape.

Electrons move like light in three-dimensional solid

Apr 22, 2015

Electrons were observed to travel in a solid at an unusually high velocity, which remained the same independent of the electron energy. This anomalous light-like behavior is found in special two-dimensional ...

Quantum model helps solve mysteries of water

Apr 20, 2015

Water is one of the most common and extensively studied substances on earth. It is vital for all known forms of life but its unique behaviour has yet to be explained in terms of the properties of individual ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.