Dresden 2014 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 81: Oxide and Insulator Surfaces III
O 81.4: Vortrag
Donnerstag, 3. April 2014, 16:45–17:00, PHY C 213
Metal nucleation and clusters on ultrathin ZrO2 films — Joong-Il J. Choi1, Ilaria Valenti2, Wernfried Mayr-Schmölzer1, Florian Mittendorfer1, Josef Redinger1, Ulrike Diebold1, and •Michael Schmid1 — 1Institut f. Angewandte Physik, TU Wien, Austria — 2Università degli Studi di Modena e Reggio Emilia, Modena, Italia
Zirconia (ZrO2) is used as a catalyst support and solid-state electrolyte in gas sensors and solid-oxide fuel cells. Nevertheless, its surface properties are insufficiently understood, mainly due to its insulating nature. To overcome this problem, we use ultrathin ZrO2 films [1,2], which are accessible to scanning tunneling microscopy (STM). We have studied nucleation and growth of Ag, Au and Pd on these ZrO2 films at room temperature. Compared to other ultrathin oxides like alumina or FeO, we find a high density of metal clusters or even single metal adatoms. Comparison between ZrO2 grown on Pd3Zr(0001) and Pt3Zr(0001) indicates that the buckling of the Zr atoms in these oxide films plays an important role, which means that metal atoms can easily bind to Zr in the oxide, as already suggested in Ref. [1]. This explains the high nucleation density and also suggests that the various crystallographic phases of bulk ZrO2 differ significantly in their surface properties.
[1] M. Antlanger et al., Phys. Rev. B 86, 035451 (2012)
J.I.J Choi et al., submitted (2013)