Gate-tunable magnetism of C adatoms on graphene

Abstract

We have performed density functional theory calculations of graphene decorated with carbon adatoms, which bind at the bridge site of a C-C bond. Earlier studies have shown that the C adatoms have magnetic moments and have suggested the possibility of ferromagnetism with high Curie temperature. Here we propose to use a gate voltage to fine tune the magnetic moments from zero to 1 µB while changing the magnetic coupling from antiferromagnetism to ferromagnetism and again to antiferromagnetism. These results are rationalized within the Stoner and RKKY models. When the SCAN meta-GGA correction is used, the magnetic moments for zero gate voltage are reduced and the Stoner band ferromagnetism is slightly weakened in the ferromagnetic region.

Observation of critical magnetic behavior in 2D carbon based composites

“…A recently published paper showed that gate-tunable magnetism could even be attained by putting C adatoms in the graphene structure. 9 When the impurity spins couple with the conduction electron spins, as shown in Fig. 1 , different kinds of magnetism, like paramagnetism, ferromagnetism, antiferromagnetism or spin glass type behavior, can be obtained in 2D carbon based composites according to the coupling of the spins within the material.…”

First‐Principles Study of the Effects of La2+/3+ Doping and Oxygen Vacancies on TiO2 Magnetism, Carrier Lifetime, Activity, and Absorption Spectra

“…The energy levels of the R.Ti 15 La 2þ O 31 and A.Ti 15 La 2þ O 31 systems were split. This finding is due to Stoner's theory, [33] which shows that when the external magnetic field h = 0, if the number of upspin and downspin electrons is not equal, n " 6 ¼ n # . As shown in Figure 3e, the built-in magnetic field and multibody effect in the A.Ti 15 La 2þ O 31 system were greater than the Burstein-Moss effect in the system; therefore, the bandgap in the A.Ti 15 La 2þ O 31 system became narrower.…”