Pyrite (FeS₂) is the most common sulfide mineral on earth and an important electron source in many geo- and biochemical reactions. In the prebiotic world, in a scenario called “iron-sulphur world“, pyrite surfaces might have played an important role in the formation of complex biomolecules, by  providing with the external surface a preferential adsorption site acting as templates for the adsorption of amino acid molecules in an laterally ordered pattern. This was shown for the simplest amino acid glycine in numerical simulations so far. Now the adsorption of glycine on pyrite surfaces should be investigated experimentally with GIXRD. Thereby, in the iron-sulphur world as well as in ambient conditions, water plays an important role. It has to be examined, how the adsorption of the amino acid competes with the hydration of the surface and how the surface structure itself is affected by the amount of water (gaseous or liquid) in the environment.
The experimental method used here is grazing incidence X-ray diffraction (GIXRD), which was already proved to be a suitable tool for the analysis of single crystal surfaces and mineral/adsorbate interfaces in experiments on calcite and fluoro-apatite at ambient conditions.

Within the scope of this project at the Institut für Geologie, Mineralogie und Gerphysik of the Ruhr-Universität Bochum (chair of crystallography) a

supported by the Deutsche Forschungsgemeinschaft with the aim of a PhD degree is available. The position is limited to a period of two years and can be extended by a maximum of another additional year.
Aim of the reasearch project (doctoral thesis) is the investigation of the atomic structure of the (100)- and (210)-surfaces of natural pyrite single crystals in ambient conditions (at room temperature, normal pressure and dry atmosphere) and at different hydration stages (humid atmosphere, liquid water film). Consecutively the interaction of pyrite surfaces with simple amino acids (glycine) in aqeous solution should be analysed and compared with theoretical simulations of the iron-sulphur world.
The main method applied in this project is grazing incidence X-ray diffraction with synchrotron radiation. The analysis of the experimental data will be complemented by forcefield-based structure simulations.

The PhD-candidate in Bochum will work mainly on the complex analysis of the experimental GIXRD-data. Accomplishment and analysis of the experiments are carried out in collaboration with Dr. X. Torrelles from ICMAB, Barcelona, Spain, so several visits to Barcelona for learning to handle the analysis software and for the optimization of the structure refinement are planned. GIXRD experiments are carried out at the ESRF, Grenoble, France, average beamtime is one week. Three data sets of pyrite were measured during the last beamtime in 12/2007 and are ready for analysis. The candidate will propose, prepare and accomplish following beamtimes, in collaboration with Dr. Torrelles. Surface topography and roughness of the pyrite single crystal sample will be checked with the atomic force microscope (AFM) at our institute in Bochum. Here also additional forcefield simulations will be carried out in collaboration with PD Dr. K. Angemund, MPI f. Kohlenforschung, Mülheim a.d. Ruhr, Germany.

The candidate should hold a diploma or MSc in physics, chemistry, mineralogy or geosciences. A good physical and mathematical background for understandig surface diffraction techniques and for the accomplishment of experiments and data analysis is expected. The ability for doing independent scientific work, flexibility as well as good teamwork are expected. The candidate should have good knowledge of the English and German language (if possible). Theoretical or practical knowledge or skills in using X-ray diffraction techniques will be helpful, but are not required.

The Ruhr-Universität Bochum is committed to equal opportunity in employment and gender equality in its working environment. To increase gender distribution in all job categories and at all levels, we strongly encourage applications from qualified woman.
Applications from appropriately qualified handicapped persons are also encouraged.

Application with the usual documents (c.v., research interests, copies of diploma/MSc, parts of the diploma or Master thesis, publications (if available)), as well as further questions can be submitted by mail or email to:

Dr. Uta Magdans
Institut für Geologie, Mineralogie und Geophysik
Ruhr-Universität Bochum
Universitätsstr. 150
44789 Bochum
Tel.: +49(0) 234/32 27546
email: uta.magdans@rub.de