Semi-empirical approaches of surface phenomena: Pt and Ni adatoms on Pt(111) and Ni(111)

Majerus, J. N.; Castellani, Norberto J.; Légaré, P.

doi:10.1016/0039-6028(94)90469-3

Cited by 4 publications

(2 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Concerning the STM experiment, it has been pointed out by the authors that small-cluster mobility could affect the Monte-Carlo estimate of the barrier if its energy is close to that for adatom diffusion, in which case the quoted value would be a lower bound to the actual barrier. As a final point, it should be mentioned that many different empirical potentials have been used to determine the diffusion barrier of Pt adatoms on Pt(111), 10,[59][60][61][62][63] yielding to values in the range 0.01-0.18 eV, i.e., much lower than the experimental value, which we argue, is a lower bound to the actual barrier. Thus, such models are clearly too crude to provide a proper description of the energetics of diffusion for the present system.…”

Section: Atom Adsorption and Diffusionmentioning

confidence: 88%

Island morphology and adatom self-diffusion on Pt(111)

1998

View full text Add to dashboard Cite

The results of a density-functional-theory study of the formation energies of (100)- and (111)-faceted steps on the Pt(111) surface, as well as of the barrier for diffusion of an adatom on the flat surface, are presented. The step formation energies are found to be in a ratio of 0.88 in favour of the (111)-faceted step, in excellent agreement with experiment; the equilibrium shape of islands should therefore clearly be non-hexagonal. The origin of the difference between the two steps is discussed in terms of the release of stress at the surface through relaxation. For the diffusion barrier, we also find relaxation to be important, leading to a 20% decrease of its energy. The value we obtain, 0.33 eV, however remains higher than available experimental data; possible reasons for this discrepancy are discussed. We find the ratio of step formation energies and the diffusion barrier to be the same whether using the local-density approximation or the generalized-gradient approximation for the exchange-and-correlation energy.Comment: Submitted to Physical Review B; 11 postscript pages including 4 figures; this and related publications available from web sites at http://www.centrcn.umontreal.ca/~lewis and http://www.fhi-berlin.mpg.de/th/th.htm

show abstract

Section: Atom Adsorption and Diffusionmentioning

confidence: 88%

Island morphology and adatom self-diffusion on Pt(111)

1998

View full text Add to dashboard Cite

show abstract

“…Tsai and Hass [16] applied a slightly modified version of the all-electron, full-potential pseudofunction (PSF) method. From the late 1980s on, several authors [17,18] applied the semi-empirical embedded-atom method (EAM) for the determination of multilayer relaxation and the surface energy. Smith et al [19] and Rodríguez et al [20] used the semi-empirical equivalent-crystal theory (ECT) for studying the same properties.…”

Section: Introductionmentioning

confidence: 99%

Periodic density functional theory study of Pt(111): surface features of slabs of different thicknesses

Kokalj

Causa

1999

J. Phys.: Condens. Matter

View full text Add to dashboard Cite

Bulk platinum and platinum slabs one to four (111) layers thick have been studied using the HF and DFT CO-LCAO (Hartree-Fock and density functional theory crystalline-orbital and linear-combination-of-atomic-orbitals) CRYSTAL program. The objective of this paper is to test the suitability of slabs of different thicknesses for modelling the (111) surface of platinum. The cohesive properties of the bulk (lattice constant, bulk modulus, cohesive energy) are reported and the electronic structure of the platinum bulk is discussed. The surface and relaxation energies as well as the relaxation distances of the slabs were evaluated. The electronic structure of the slabs is discussed in terms of Mulliken population analysis, the density of states, the band structure and electron-density difference maps. `Initial-state' surface-atom core-level shifts are reported, as well as atomic dipole and quadrupole moments perpendicular to the surface.

show abstract