Diverse Electronic and Magnetic Properties of Chlorination-Related Graphene Nanoribbons

TL;DR

This study uses first-principles calculations to explore how halogen adatoms like Cl, Br, I, and At alter the electronic and magnetic properties of graphene nanoribbons, revealing diverse magnetic states and doping effects.

Contribution

It provides a comprehensive analysis of halogen adsorption effects on graphene nanoribbons, highlighting the dependence on adatom concentration and edge structure for electronic and magnetic properties.

Findings

Halogen adsorption induces various magnetic states, including non-magnetic, ferromagnetic, and antiferromagnetic metals.

Adatom concentration influences charge doping and magnetic behavior, with magnetism disappearing beyond 60% coverage.

Rich spin-dependent features such as van Hove singularities are observed in the density of states.

Abstract

The dramatic changes in electronic and magnetic properties are investigated using the first-principles calculations for (Cl, Br, I, At)-adsorbed graphene nanoribbons. The rich and unique features are clearly revealed in the adatom-dominated band structures, p-type doping, spin arrangement/magnetic moment, spatial charge distribution, and orbital- and spin-projected density of states. Halogen adsorptions can create the non-magnetic, ferromagnetic or anti-ferromagnetic metals, being mainly determined by concentrations and edge structures. The number of holes per unit cell increases with the adatom concentrations. Furthermore, magnetism becomes nonmagnetic when the adatom concentration is beyond 60 % adsorption. There are many low-lying spin-dependent van Hove singularities. The diversified properties are attributed to the significant X-C bonds, the strong X-X bonds, and the adatom- and edge-carbon-induced spin states.