Abstract
We present an ab initio density-functional study for aluminium adsorption on Ir(1 1 1) at high symmetry sites, namely, the fcc-, hcp-hollow, top and bridge sites. In each case, we calculate the atomic geometry, average binding energy, work function, and surface dipole moment at the coverage of 0.25 monolayer. We find the favourable structure to be Al at threefold hcp-hollow site, with a corresponding binding energy of 4.46 eV. We present and compare the electronic properties of the two lowest energy structures, i.e., at the threefold hollow sites and discuss the nature of the Al-Ir bond and binding site preference. In particular, we observe a large hybridization of Al-3s, 3p and Ir-5d states near Fermi level, forming an inter-metallic bonds. This results in a significant electron transfer from the Al atoms to the Ir(1 1 1) substrate, inducing an outward pointing surface dipole moment and a large decrease in the work function of 1.69 eV for Al in the hcp-hollow site. Compared to the fcc-hollow site, adsorption in the hcp-hollow site results in a lower density-of-states at the Fermi level, as well as a greater hybridization in the bonding states.
| Original language | English |
|---|---|
| Pages (from-to) | 7655-7658 |
| Number of pages | 4 |
| Journal | Applied Surface Science |
| Volume | 254 |
| Issue number | 23 |
| DOIs | |
| Publication status | Published - 2008 Sep 30 |
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All Science Journal Classification (ASJC) codes
- Surfaces, Coatings and Films
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Aluminium adsorption on Ir(1 1 1) at a quarter monolayer coverage : A first-principles study. / Zhang, Hong; Soon, Aloysius; Delley, Bernard; Stampfl, Catherine.
In: Applied Surface Science, Vol. 254, No. 23, 30.09.2008, p. 7655-7658.Research output: Contribution to journal › Article
TY - JOUR
T1 - Aluminium adsorption on Ir(1 1 1) at a quarter monolayer coverage
T2 - A first-principles study
AU - Zhang, Hong
AU - Soon, Aloysius
AU - Delley, Bernard
AU - Stampfl, Catherine
PY - 2008/9/30
Y1 - 2008/9/30
N2 - We present an ab initio density-functional study for aluminium adsorption on Ir(1 1 1) at high symmetry sites, namely, the fcc-, hcp-hollow, top and bridge sites. In each case, we calculate the atomic geometry, average binding energy, work function, and surface dipole moment at the coverage of 0.25 monolayer. We find the favourable structure to be Al at threefold hcp-hollow site, with a corresponding binding energy of 4.46 eV. We present and compare the electronic properties of the two lowest energy structures, i.e., at the threefold hollow sites and discuss the nature of the Al-Ir bond and binding site preference. In particular, we observe a large hybridization of Al-3s, 3p and Ir-5d states near Fermi level, forming an inter-metallic bonds. This results in a significant electron transfer from the Al atoms to the Ir(1 1 1) substrate, inducing an outward pointing surface dipole moment and a large decrease in the work function of 1.69 eV for Al in the hcp-hollow site. Compared to the fcc-hollow site, adsorption in the hcp-hollow site results in a lower density-of-states at the Fermi level, as well as a greater hybridization in the bonding states.
AB - We present an ab initio density-functional study for aluminium adsorption on Ir(1 1 1) at high symmetry sites, namely, the fcc-, hcp-hollow, top and bridge sites. In each case, we calculate the atomic geometry, average binding energy, work function, and surface dipole moment at the coverage of 0.25 monolayer. We find the favourable structure to be Al at threefold hcp-hollow site, with a corresponding binding energy of 4.46 eV. We present and compare the electronic properties of the two lowest energy structures, i.e., at the threefold hollow sites and discuss the nature of the Al-Ir bond and binding site preference. In particular, we observe a large hybridization of Al-3s, 3p and Ir-5d states near Fermi level, forming an inter-metallic bonds. This results in a significant electron transfer from the Al atoms to the Ir(1 1 1) substrate, inducing an outward pointing surface dipole moment and a large decrease in the work function of 1.69 eV for Al in the hcp-hollow site. Compared to the fcc-hollow site, adsorption in the hcp-hollow site results in a lower density-of-states at the Fermi level, as well as a greater hybridization in the bonding states.
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U2 - 10.1016/j.apsusc.2008.01.160
DO - 10.1016/j.apsusc.2008.01.160
M3 - Article
VL - 254
SP - 7655
EP - 7658
JO - Applied Surface Science
JF - Applied Surface Science
SN - 0169-4332
IS - 23
ER -