A LEED analysis of the CoO(100) surface

Low-energy electron diffraction structure determination of an ultrathin CoO film on Ag(001)

“…Fig. 3 compares the (1 1), (2 0) and (2 1) I(V) curves of the cobalt oxide film on Ag(0 0 1) and the (0 0 1) surface of a CoO single crystal as published [2]. The similarity of the two sets of curves confirms that the oxide in the film is actually CoO with rocksalt structure.…”

“…As mentioned above, a previous surface structure determination of the (0 0 1) surface of a CoO single crystal did not find any relaxations, although with a larger error bar of AE3% [2]. We attribute this obvious difference to the fact that the CoO film grows pseudomorphically on Ag(0 0 1), which results in a compression in both lateral directions.…”

“…Comparing the experiments of the two systems (bulk and thin film) reveals another advantage of thin films of insulating materials. In the case of the bulk single crystal charging effects prevented the recording of I(V) curves below 170 eV [2], whereas in the case of the thin film, charges created in the film present no problem as they are easily transferred to the metallic Ag substrate. As a result the intensity of the (1 0) spot could be recorded from an energy as low as 30 eV, as evident from Fig.…”

“…A structure determination of the (0 0 1) surface of a CoO single crystal revealed no significant deviation from a bulk terminated surface [2]. Compared to metal surfaces two additional origins of surface relaxations have to be considered in thin films of oxides.…”

Molecular modelling of the decomposition of NH3 over CoO(100)

“…The first and second relaxed interlayer distances increased only by~0.04 Å (~2%) from the 2.14 Å bulk layer spacing. The minor surface relaxations are consistent with experimental observation using LEED measurements on a UHV cleaved CoO(100) surface in which changes in interlayers distancing as a result of surface relaxations were reported to be within ±3% compared to the bulk CoO [40]. We observed a break in the surface symmetry in the spin-polarised PBE þ U calculations, resulting in the CoeO bond lengths in the top-most layer varying between 2.12 Å and 2.17 Å.…”