Figure 5: Spin densities and densities of states.
From: Room temperature organic magnets derived from sp3 functionalized graphene
(a,b) The m-xylylene-like motif (green) of G(OH)F embedded in an sp3 lattice with the corresponding FM (a) and AFM (b) phases, with up/down spin densities shown in yellow/blue. (c,d) sp3-embedded trimethylenemethane-like motif with the corresponding FM spin density. Brown/green, blue, red and pink balls represent carbon, fluorine, oxygen and hydrogen atoms, respectively. (e) DOS of the GS FM phase. (f) DOS of the AFM phase. For (e) and (f), orbital contributions of individual atoms (labelled in the inset legend) are presented in both spectra. Electronic states of carbon atoms with up/down magnetic moments are plotted by brown/black line. Electronic states with the same spin direction can hybridize with each other. The hybridization involves the occupied and unoccupied spin-up states (e) and the occupied and unoccupied spin-up or spin-down states (f). Such kind of coupling not involving a finite density of states at EF is termed as the superexchange interaction. Both DOS spectra show a significant contribution of oxygen orbitals to the midgap states, which implies an important role of -OH group in the superexchange interactions.
