Fluorine-induced local magnetic moment in graphene: A hybrid DFT study

TL;DR

This study demonstrates that hybrid DFT calculations reveal the formation of local magnetic moments in fluorinated graphene, aligning with experimental findings, unlike previous semilocal DFT predictions.

Contribution

The paper shows that hybrid DFT overcomes self-interaction errors in semilocal DFT, accurately predicting magnetic moments induced by fluorine adatoms in graphene.

Findings

Hybrid DFT predicts a spin moment of 1 Bohr magneton for F adatoms.

Long-range spin polarization occurs due to graphene's bipartite lattice.

Results support experimental evidence of magnetic moments in fluorinated graphene.

Abstract

Recent experimental evidence that fluorinated graphene creates local magnetic moments around F adatoms has not been supported by semilocal density-functional theory (DFT) calculations where the adsorption of an isolated F adatom induces no magnetic moment in graphene. Here, we show that such an incorrect prediction of the nonmagnetic ground state is due to the self-interaction error inherent in semilocal exchange-correlation functionals. The present hybrid DFT calculation for an isolated F adatom on graphene predicts not only a spin-polarized ground state with a spin moment of 1 bohr magneton, but also a long-range spin polarization caused by the bipartite nature of the graphene lattice as well as the induced spin polarization of the graphene states. The results provide support for the experimental observations of local magnetic moments in fluorinated graphene.