Adatoms and Clusters of 3d Transition Metals on Graphene: Electronic and Magnetic Configurations
Abstract
We investigate the electronic and magnetic properties of single Fe, Co, and Ni atoms and clusters on monolayer graphene (MLG) on SiC(0001) by means of scanning tunneling microscopy (STM), x-ray absorption spectroscopy, x-ray magnetic circular dichroism (XMCD), and ab initio calculations. STM reveals different adsorption sites for Ni and Co adatoms. XMCD proves Fe and Co adatoms to be paramagnetic and to exhibit an out-of-plane easy axis in agreement with theory. In contrast, we experimentally find a nonmagnetic ground state for Ni monomers while an increasing cluster size leads to sizeable magnetic moments. These observations are well reproduced by our calculations and reveal the importance of hybridization effects and intra-atomic charge transfer for the properties of adatoms and clusters on MLG.
- Publication:
-
Physical Review Letters
- Pub Date:
- March 2013
- DOI:
- 10.1103/PhysRevLett.110.136804
- arXiv:
- arXiv:1304.6833
- Bibcode:
- 2013PhRvL.110m6804E
- Keywords:
-
- 73.20.Hb;
- 71.15.Mb;
- 73.22.Pr;
- 78.70.Dm;
- Impurity and defect levels;
- energy states of adsorbed species;
- Density functional theory local density approximation gradient and other corrections;
- X-ray absorption spectra;
- Condensed Matter - Mesoscale and Nanoscale Physics;
- Condensed Matter - Materials Science
- E-Print:
- 8 pages (supplementary included), 4 figures, (supplementary included)