Adsorption and growth morphology of rare-earth metals on graphene studied by ab initio calculations and scanning tunneling microscopy

TitleAdsorption and growth morphology of rare-earth metals on graphene studied by ab initio calculations and scanning tunneling microscopy
Publication TypeJournal Article
Year of Publication2010
AuthorsLiu XJ, Wang CZ, Hupalo M, Yao YX, Tringides MC, Lu WC, Ho KM
Journal TitlePhysical Review B
Volume82
Pages245408
Date Published12
Type of ArticleArticle
ISBN Number1098-0121
Accession NumberWOS:000286895700006
Keywordsaugmented-wave method, basis-set, films, total-energy calculations
Abstract

Adsorption of rare-earth (RE) adatoms (Nd, Gd, Eu, and Yb) on graphene was studied by first-principles calculations based on the density-functional theory. The calculations show that the hollow site of graphene is the energetically favorable adsorption site for all the RE adatoms studied. The adsorption energies and diffusion barriers of Nd and Gd on graphene are found to be larger than those of Eu and Yb. Comparison with scanning tunneling microscopy experiments for Gd and Eu epitaxially grown on graphene confirms these calculated adsorption and barrier differences, since fractal-like islands are observed for Gd and flat-topped crystalline islands for Eu. The formation of flat Eu islands on graphene can be attributed to its low diffusion barrier and relatively larger ratio of adsorption energy to its bulk cohesive energy. The interactions between the Nd and Gd adatoms and graphene cause noticeable in-plane lattice distortions in the graphene layer. Adsorption of the RE adatoms on graphene also induces significant electric dipole and magnetic moments.

URL<Go to ISI>://WOS:000286895700006
DOI24540810.1103/PhysRevB.82.245408
Alternate JournalPhys. Rev. B