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Dr. Alexei Nefedov

Dr. Alexei Nefedov

+49-721-608-2-3551
+49-721-608-2-3478
E-Mail

 

UHV-IR/XPS

PREVAC 

 

The new state-of-the-art ultrahigh vacuum system UHV-IR/XPS made by PREVAC in IFG is equipped with best surface science techniques. The UHV- apparatus exists of a distribution chamber, two preparation chambers, an analysis chamber, an infrared (IR) – chamber, two load-locks and a magazine.

The preparation chambers give the opportunity to sputter, for cleaning the sample, to heat (max. 1200 K or 2000 K stand-alone) and to cool the sample (max. 70 K) on one same sample holder. Molecules and metals can be evaporated on the surface and detected by LEED, Auger electron spectroscopy, and mass spectrometry. The desorption process can be traced by thermal desorption spectroscopy.

Powder as well as single crystals and other solid material can be investigated in the IR- and the analysis chamber. Heating to 1200 K and cooling with liquid nitrogen to 100 K is possible in every chamber. In the analysis chamber the sample can be prepared with sputtering and annealing, it is also possible to cool the sample.

The photoelectron spectroscopy techniques in the analysis chamber are giving information about the elemental composition of the surface (top 1–10 nm usually), the empirical formula of pure materials, chemical or electronic state of each element in the surface and uniformity of elemental composition across the top surface (or line profiling, mapping, and depth profiling with both sputtering and angle resolving in tilting or non-tilting specimen modes).

In the IR chamber samples could be measured in transmission or reflection mode (Reflection Absorption Infrared Spectroscopy (RAIRS)). The Rapid Scan and Step Scan mode give also the opportunity to study the kinetics of a reaction. The samples could be heated or cooled down to 30 K and gases could be doses during the measurements. Photocatalytic experiments are planned for the IR chamber.

Our knowledge and expertise are available for all other institutes of KIT as well as external partners.

 

 

Equipment

 

  • IR: Bruker Vertex 80v


  • XPS/UPS/ARPES/AES: RG Scienta 4000


  • LEED/AES


  • TDS


  • Effusion cells, evaporators


The PhD-students are member of the Helmholtz Research School „Energy-related catalysis“.

Current Publications
Titel Autor Quelle

Yu, X. / Zhang, Z. / Yang, C. / Bebensee, F. / Heissler, S. / Nefedov, A. / Tang, M. / Ge, Q. / Chen, L. / Kay, B., D. / Dohnalek, Z. / Wang, Y. / Wöll, C. (2016) 

J. Phys. Chem. C, 120, 12626-12636,  DOI: 10.1021/acs.jpcc.6b03689 

Buchholz, M. / Yu, X. / Yang, C. / Heißler, S. / Nefedov, A. / Wang, Y. / Wöll, C (2016) 

Surface Science, 2016, 652, 245-252

Yang, C. / Bebensee, F. / Nefedov, A. / Wöll, C. / Kropp, T. / Komissarov, L. / Penschke, C. / Moerer, R. / Paier, J. / Sauer, J. (2016) 

Journal of Catalysis, (2016), 336, 116–125 

Buchholz, M. / Xu, M. / Heshmat, N. / Weidler, P. / Nefedov, A. / Finke, A. / Wang, Y. / Wöll, C. (2016) 

doi:10.1016/j.susc.2015.08.006


Xiaojuan Yu, Zhengbang Wang, Maria Buchholz, Nena Füllgrabe, Sylvain Grosjean, Fabian Bebensee, Stefan Bräse, Christof Wöll and Lars Heinke
 

Phys. Chem. Chem. Phys., (2015), 17,  22721-22725

Sezen, H. / Shang, H. / Bebensee, F. / Yang, C. / Buchholz, M. / Nefedov, A. / Heissler, S. / Carbogno, C. / Scheffler, M. / Rinke, P. / Wöll, C. (2015) 

Nature Communications, 6, 6901(1-4), doi:10.1038/ncomms7901 

Maria Buchholz, M. / Li, Q. / Noei, H. / Nefedov, A. / Wang, Y. / Muhler, M. / Fink, K. / Wöll, C. (2015)

Topics in Catalysis, (2015), 58, 2, 174-183