TY - JOUR
T1 - Metal-metal interfacial bonding
T2 - monolayer c(2 × 2) Cu on a Pt(001) surface
AU - Kramar, T.
AU - Podloucky, R.
AU - Neckel, A.
AU - Erschbaumer, H.
AU - Freeman, A. J.
N1 - Funding Information:
This work was supported by the Austrian Science Foundation (Fonds zur Forderung der Wiss-enschaftlichen Forschung, project No. 7122-PHY), by the US Office of Naval Research (Grant No. N00014-89-J-1290), by the US National Science Foundation (Grant No. INT89-09851, and a computing grant from its Division of Advanced Scientific Computing at the Pittsburgh Supercomputing Center) and by CRAY Research (Germany). Part of the calculations were done on the EASI facilities of the Computing Centre at the University of Vienna.
PY - 1991/5/1
Y1 - 1991/5/1
N2 - First steps in understanding from first principles the underpotential electrodeposition of a metal (Cu) onto the surface of another metal (Pt) are reported. Results of local density full potential linearized augmented plane wave calculations for a slab consisting of five layers of Pt(001) with a Cu monolayer of c(2 × 2) geometry on top of each surface are presented. Minimization of the total energy as a function of the distance between the uppermost Pt layer and the Cu layer yielded a shrinkage of the CuPt nearest-neighbor distance by 13%. This result illustrates the very strong bonding between the Cu adsorbate and the Pt(001) substrate in agreement with measurements of electrochemical underpotentials. A comparison of the density of states (DOS) of the overlayer system with the DOS of an isolated slab of Pt and the DOS of a single Cu monolayer shows that energetically the Cu d-states coincide with the Pt surface states. The analysis of the bonding charge density shows a strong build up of charge in-between the CuPt neighbors, a smoothening of the corrugation, and also an increase of the Pt interlayer bonding. The nature of the chemical bonding between adsorbate and substrate atoms is examined with a discussion of the charge distribution of several special occupied electronic states.
AB - First steps in understanding from first principles the underpotential electrodeposition of a metal (Cu) onto the surface of another metal (Pt) are reported. Results of local density full potential linearized augmented plane wave calculations for a slab consisting of five layers of Pt(001) with a Cu monolayer of c(2 × 2) geometry on top of each surface are presented. Minimization of the total energy as a function of the distance between the uppermost Pt layer and the Cu layer yielded a shrinkage of the CuPt nearest-neighbor distance by 13%. This result illustrates the very strong bonding between the Cu adsorbate and the Pt(001) substrate in agreement with measurements of electrochemical underpotentials. A comparison of the density of states (DOS) of the overlayer system with the DOS of an isolated slab of Pt and the DOS of a single Cu monolayer shows that energetically the Cu d-states coincide with the Pt surface states. The analysis of the bonding charge density shows a strong build up of charge in-between the CuPt neighbors, a smoothening of the corrugation, and also an increase of the Pt interlayer bonding. The nature of the chemical bonding between adsorbate and substrate atoms is examined with a discussion of the charge distribution of several special occupied electronic states.
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U2 - 10.1016/0039-6028(91)90195-X
DO - 10.1016/0039-6028(91)90195-X
M3 - Article
AN - SCOPUS:0026155197
VL - 247
SP - 58
EP - 68
JO - Surface Science
JF - Surface Science
SN - 0039-6028
IS - 1
ER -