The adsorption of CO molecules at the Ca3Ru2O7(001) surface was studied using low-temperature scanning tunneling microscopy (STM) and density functional theory (DFT). Ca3Ru2O7 can be easily cleaved along the (001) plane, yielding a smooth, CaO-terminated surface. The STM shows a characteristic pattern with alternating dark and bright stripes, resulting from the tilting of the RuO6 octahedra. At 78,K, CO adsorbs at an apical surface O at the channel edge with a predicted binding energy of Eads=−0.85eV. After annealing at room temperature, the CO forms a strong bond (Eads=−2.04eV) with the apical O and the resulting carboxylate takes the place of the former surface O. This carboxylate can be decomposed by scanning the surface with a high sample bias voltage of +2.7V, restoring the original surface.
@article{arxiv.1810.01186,
title = {Adsorption of CO on the Ca3Ru2O7(001) surface},
author = {Wernfried Mayr-Schmölzer and Daniel Halwidl and Florian Mittendorfer and Michael Schmid and Ulrike Diebold and Josef Redinger},
journal= {arXiv preprint arXiv:1810.01186},
year = {2018}
}