Density functional study of alkali metal atoms and monolayers on graphite (0001)

Details Density functional study of alkali metal atoms and monolayers on graphite (0001) Density functional study of alkali metal atoms and monolayers on graphite (0001)

2006-09-19

arxiv.org/abs/cond-mat/0609458v1

Physics

Condensed Matter

Materials Science

6 figures

Scientific paper

10.1103/PhysRevB.75.075401

Alkali metal atoms (Li, Na, K, Rb, Cs), dimers and (2$\times$2) monolayers on a graphite (0001) surface have been studied using density functional theory, pseudopotentials, and a periodic substrate. The adatoms bind at the hollow site (graphite hexagon), with Li lying closest to (1.84 \AA) and Cs farthest (3.75 {\AA}) from the surface. The adsorption energies range between $0.55-1.21$ eV, and the energy ordering of the alkali adatoms is Li$>$Cs$\ge$Rb$\ge$K$>$Na. The small diffusion barriers (0.02-0.21 eV for the C-C bridge) decrease as the atom size increases, indicating a flat potential energy surface. The formation (cohesion) energies of (2$\times$2) monolayers range between 0.55-0.81 eV, where K has the largest value, and increased coverage weakens the adsorbate-substrate interaction (decoupling) while a two-dimensional metallic film is formed. Analysis of the charge density redistribution upon adsorption shows that the alkali metal adatoms donate a charge of $0.4-0.5 e$ to graphite, and the corresponding values for (2$\times$2) monolayers are $\sim 0.1 e$ per atom. The transferred charge resides mostly in the $\pi$-bands (atomic $p_z$-orbitals) of the outermost graphene layer.

Affiliated with

Also associated with

No associations

Rating

Density functional study of alkali metal atoms and monolayers on graphite (0001) does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Density functional study of alkali metal atoms and monolayers on graphite (0001), we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Density functional study of alkali metal atoms and monolayers on graphite (0001) will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-465443