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Publications in Scientific Journals:

J. Hulva, Z. Jakub, Z. Novotny, N. Johansson, J. Knudsen, A. Schnadt, M. Schmid, U. Diebold, G. Parkinson:
"Adsorption of CO on the Fe3O4(001) Surface";
Journal of Physical Chemistry B, 122 (2018), 721 - 729.



English abstract:
The interaction of CO with the Fe3O4(001)-
(√2 √2)R45 surface was studied using temperatureprogrammed
desorption (TPD), scanning tunneling microscopy
(STM), and X-ray photoelectron spectroscopy (XPS),
the latter both under ultrahigh vacuum (UHV) conditions and
in CO pressures up to 1 mbar. In general, the CO−Fe3O4
interaction is found to be weak. The strongest adsorption
occurs at surface defects, leading to small TPD peaks at 115,
130, and 190 K. Desorption from the regular surface occurs in
two distinct regimes. For coverages up to two CO molecules
per (√2 √2)R45 unit cell, the desorption maximum
shows a large shift with increasing coverage, from initially 105
to 70 K. For coverages between 2 and 4 molecules per (√2 √2)R45 unit cell, a much sharper desorption feature emerges at
∼65 K. Thermodynamic analysis of the TPD data suggests a phase transition from a dilute 2D gas into an ordered overlayer with
CO molecules bound to surface Fe3+ sites. XPS data acquired at 45 K in UHV are consistent with physisorption. Some carboncontaining
species are observed in the near-ambient-pressure XPS experiments at room temperature but are attributed to
contamination and/or reaction with CO with water from the residual gas. No evidence was found for surface reduction or
carburization by CO molecules.

Created from the Publication Database of the Vienna University of Technology.