Mc. Desjonqueres et al., A SIMPLE APPROACH TO THE CALCULATION OF SURFACE DEFECT ENERGIES IN TRANSITION-METALS, Applied surface science, 87-8(1-4), 1995, pp. 337-346
Citations number
32
Categorie Soggetti
Physics, Condensed Matter","Chemistry Physical","Materials Science, Coatings & Films
In order to understand the energetics of various atomic processes invo
lved in crystal growth, we have developed a simple approach for calcul
ating surface defect energies in transition metals. The total energy o
f each system is split into two contributions: an attractive term whic
h is due to the broadening of d atomic levels (band contribution) and
a repulsive one written as a sum of pairwise interactions (Born-Mayer
potential). The band contribution is calculated in the tight-binding a
pproximation. Both the pairwise repulsive interaction and the tight-bi
nding hopping integrals are assumed to decrease exponentially when the
interatomic distance increases and the equilibrium geometry can be de
termined from total energy minimization. A few examples aiming at inte
rpreting some field ion microscopy experiments carried out on transiti
on metals will be presented: interaction of an adsorbate with a surfac
e step, relative stability of normal (bulk) and fault (surface) adsorp
tion sites on the close-packed (111) fee and (0001) hcp surfaces and o
f islands of adatoms on (111) fee surfaces.