# Fundamental properties of transition-metals-adsorbed graphene

## TL;DR

This study uses first-principles calculations to explore the structural, electronic, and magnetic properties of transition metal-doped graphene, revealing diverse behaviors including metallicity and magnetism depending on the dopant and concentration.

## Contribution

It provides a comprehensive analysis of transition metal doping effects on graphene's properties, including detailed insights into bonding, electronic structure, and magnetism, which were not fully characterized before.

## Key findings

- Most doped systems are metallic, except low-concentration Ni-doped graphene.
- Ferromagnetism appears in Fe/Co-doped systems and high Ni-concentration samples.
- The study's predictions align well with experimental data.

## Abstract

The revealing properties of transition metal (T)-doped graphene systems are investigated with the use of the first-principles method. The detailed calculations cover the bond length, position and height of adatoms, binding energy, atom-dominated band structure, adatom-induced free carrier density as well as energy gap, spin-density distributions, spatial charge distribution, and atom-, orbital- and spin-projected density-of-states (DOS). The magnetic configurations are clearly identified from the total magnetic moments, spin-split energy bands, spin-density distributions and spin-decomposed DOS. Moreover, the single- or multi-orbital hybridizations in T-C, T-T, and C-C bonds can be accurately deduced from the careful analyses of the above-mentioned physical quantities. They are responsible for the optimal geometric structure, the unusual electronic properties, as well as the diverse magnetic properties. All the doped systems are metals except for the low-concentration Ni-doped ones with semiconducting behavior. In contrast, ferromagnetism is exhibited in various Fe/Co-concentrations but only under high Ni-concentrations. Our theoretical predictions are compared with available experimental data, and potential applications are also discussed.