Adsorption of CO on the Ca3Ru2O7(001) surface

Abstract

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 RuO${}_6$ octahedra. At 78,K, CO adsorbs at an apical surface O at the channel edge with a predicted binding energy of $E_{ads}=-0.85$eV. After annealing at room temperature, the CO forms a strong bond ($E_{ads}=-2.04$eV) 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.

References in corpus (7)

• Van der Waals density functionals applied to solids
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• Spin-valve effect and magnetoresistivity in single crystalline Ca3Ru2O7
• Surface and Bulk Structural Properties of Single Crystalline Sr3Ru2O7
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• Adsorption of a superoxo O2- species on the pure an Ca doped Sr3Ru2O7(001) surface