Dresden 2014 – scientific programme

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O: Fachverband Oberflächenphysik

O 81: Oxide and Insulator Surfaces III

O 81.4: Talk

Thursday, April 3, 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)