Clustering of chemisorbed H(D) atoms on the graphite (0001) surface due to preferential sticking.
We present scanning tunneling microscopy experiments and density functional theory calculations which reveal a unique mechanism for the formation of hydrogen adsorbate clusters on graphite surfaces. Our results show that diffusion of hydrogen atoms is largely inactive and that clustering is a consequence of preferential sticking into specific adsorbate structures. These surprising findings are caused by reduced or even vanishing adsorption barriers for hydrogen in the vicinity of already adsorbed H atoms on the surface and point to a possible novel route to interstellar H2 formation.
Hornekaer
L
L
Interdisciplinary Nanoscience Center (iNANO) and Department of Physics and Astronomy, University of Aarhus, Ny Munkegade bygn. 1520, 8000 Aarhus C, Denmark. liv@phys.au.dk
Rauls
E
E
Xu
W
W
Sljivancanin
Z
Z
Otero
R
R
Stensgaard
I
I
Laegsgaard
E
E
Hammer
B
B
Besenbacher
F
F