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Research

  Palladium nanoclusters: nanoscale local and electronic structure  

Palladium is often used in dentistry, watch making, in aircraft spark plugs and in the production of surgical instruments and electrical contacts. It is also used as catalyst. Palladium is the most active in nanoparticle phase.

Pd_nanoclusters

Fig. 1 Model structures of Pd nanoclusters of 13, 19, 43 and 55 atoms

X-ray absorption spectras of bulk Pd and Pd nanoclusters reveal differences in these objects. To find out geometry structure of nanoclusters geometry optimization was made by means of density functional theory (DFT). Local atomic structure of optimized nanocluster differs significantly from fragment of lattice of crystal Pd with the same number of atoms. Theoretical calculations of Pd L3 XANES spectra in optimized, not optimized clusters and bulk Pd were made. It is important not to use muffin tin approximation for shape of potential during the theoretical calculation of XANES spectra for nanoclusters. For nanocluster’s spectra total XANES signal is the weighted sum of scattering by surface and central atoms. Calculations prove supposed changes in geometry structure of nanoclusters comparatively with crystal Pd.

Results of the research are published in [1]:
[1] M.A. Soldatov, G.E. Yalovega, A.V. Soldatov Local atomic and electronic structures of Pd Nanoclusters // JOURNAL OF SURFACE INVESTIGATION X-RAY, SYNCHROTRON AND NEUTRON TECHNIQUES 2009, ?7, p. 84-88

                                                                                                                                                                                                                                                     
     

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