Diffusion of N adatoms on the Fe(100) surface
The diffusion of individual N adatoms on Fe(100) has been studied using scanning tunneling microscopy and ab initio density functional theory (DFT) calculations. The measured diffusion barrier for isolated N adatoms is E(d) = (0.92+/-0.04) eV, with a prefactor of nu(0) = 4.3x10(12) s(-1), which is in quantitative agreement with the DFT calculations. The diffusion is strongly coupled to lattice distortions, and, as a consequence, the presence of other N adatoms introduces an anisotropy in the diffusion. Based on experimentally determined values of the diffusion barriers and adsorbate-adsorbate interactions, the potential energy surface experienced by a N adatom is determined.
Pedersen
MO
CAMP and Institute of Physics and Astronomy, University of Aarhus, DK 8000 Aarhus C, Denmark.
Osterlund
L
Mortensen
JJ
Mavrikakis
M
Hansen
LB
Stensgaard
I
Laegsgaard
E
Norskov
JK
Besenbacher
F