Stabilizing single Ni adatoms on a two-dimensional porous titania overlayer at the SrTiO3(110) surface

Z. Wang, X. Hao, S. Gerhold, P. Mares, M. Wagner, R. Bliem, K. Schulte, M. Schmid, C. Franchini, U. Diebold

Institut für Angewandte Physik, Technische Universität Wien, 1040 Wien, Austria
MAX IV Laboratory, Lund University, 22363 Lund, Sweden
Faculty of Physics and Center for Computational Materials Science, University of Vienna, 1090 Vienna, Austria

J. Phys. Chem C 118 (2014) 19904-19909

Nickel vapor deposited on the SrTiO3(110) surface was studied using scanning tunneling microscopy, photoemission spectroscopy (PES), and density functional theory calculations. This surface forms a (4 × 1) reconstruction, composed of a 2-D titania structure with periodic six- and ten-membered nanopores. Anchored at these nanopores, Ni single adatoms are stabilized at room temperature. PES measurements show that the Ni adatoms create an in-gap state located at 1.9 eV below the conduction band minimum and induce an upward band bending. Both experimental and theoretical results suggest that Ni adatoms are positively charged. Our study produces well-dispersed single adatom arrays on a well-characterized oxide support, providing a model system to investigate single-adatom catalytic and magnetic properties.

Corresponding author: Gareth S. Parkinson (parkinson at iap_tuwien_ac_at).

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