Scientists for many decades have been posed with the question of how to study the chemical reactions taking place during the etching and coating of materials without significant progress or success, until now that is.
For the first time, a group of scientists, headed up by Professor Olaf Magnussen at Kiel University, has uncovered what actually happens during the manufacturing processes used in the production of metal contacts used in consumer electronics, such as the ever popular flat screen television sets [Golks et al., J Am Chem Soc (2011) 133, 3772].
The scientists used an x-ray beam directed on to the surface of gold whilst it was dissolved in a dilute concentration of HCl. The sensitive x-rays were able to pick up the small changes in the atomic configuration at the materials surface during the reaction, which was measured with a high degree of precision. Thus far Professor Magnussen is quoted as saying only slow changes of the material have been measured initially. To achieve success with faster reactions, similar to those used in industrial processes, the speed of measurement had to be increased by more than two orders of magnitude. During very fast etching it was observed that the metal was removed surprisingly uniformly, as “the material dissolves quasi atomic layer by atomic layer, without formation of deeper holes”. In the same way Magnussen’s team could follow the reverse reaction; the attachment of atoms during chemical coating.
High tech manufacturing processes are among the many applications of chemical etching and coating. These methods are used in the production of electronic devices, which require precision reactions during formation, to ensure the preservation of their distinctive properties.
The findings announced in the JACS will allow scientists to actually study what is happening within the reaction, rather than just the final product itself. Changes within a few thousandths of a second may be detected so that the reaction can be tracked and controlled in a way that it has never been accomplished before.


Jonathan Agbenyega