Diluted ferromagnetic graphene by compensated n–p codoping

Abstract

In this study, we propose a new approach, based on compensated n–p codoping, that can simultaneously address all the main shortcomings associated with single-element doping, effectively resulting in “diluted ferromagnetic graphene”. Our proposal is to deposit magnetic transitional metal (TM) atoms (such as Fe, Co, and Ni), acting as n-type dopants, onto already p-doped (e.g., by B) graphene. Through systematic first-principles calculations within density functional theory, we found that: (1) the electrostatic attraction between the n- and p-type dopants effectively enhances the adsorption of the TM adatoms and suppress their undesirable clustering, (2) the p-doping by B significantly enhances the magnetic moments of the TM adatoms, and (3) the compensated nature of the n–p codoping helps to preserve the Dirac nature of the charge carriers. Furthermore, through Monte Carlo simulations of a Heisenberg model with the essential magnetic coupling parameters obtained from the first-principles calculations, we found that Ni–B codoped graphene has a robust ferromagnetic order at experimentally feasible doping concentrations, with a Curie temperature as high as 212K.