HZB scientists have apply a new method -- "inverse Partial Fluorescence Yield" (iPFY) on micro-jet -- which will enable them to probe the electronic structure of liquids free of sample damages. The experiments are performed in vacuum conditions at the LiXEdrom experimental chamber, where a fluid stream of micrometer diameter is moving freely through vacuum and is continuously irradiated with X-ray radiation.
These kinds of experiments are important as they reveal the interaction strength of the X-rays with the liquids and therefore allow for the structural analysis of substances dissolved in solution. "The method will achieve its absolute apprehension when will be applied to metal ions that are part of chemical catalysts used for clean energy production and biocatalysts (protein enzymes) used in biochemical transformation inside the living cells the team leader Prof. Aziz stated, which is the next milestone in our research progress. Previously, these types of experiments were so far only possible if the fluid was contained between two membranes, where radiation damages and membrane induced artifacts were a crucial issue. HZB's Young Investigator Group for Functional Materials in Solution headed by Prof. Dr. Emad Aziz has already applied the new method in iron ions dissolved in aqueous solution. Their findings have now been published in the Journal of Physical Chemistry Letters (DOI: 10.1021/jz300403n).
The researchers used X-ray radiation generated by HZB's own electron storage ring BESSY II to examine iron ions in aqueous solution. "We measured the absorption strength of the X-rays from our Fe 2+ and oxygen ions in the liquid micro-beam" explains Malte Gotz, who performed the experiments as part of his graduate research. "From here, we were able to draw conclusions regarding the electronic structure of the iron ions and further more to investigate the interaction of iron ions with the water solvent, " says Gotz.
|Contact: Dr. Emad F. Aziz|
Helmholtz Association of German Research Centres