Theoretical perspective on structural, electronic and magnetic properties of 3d metal tetraoxide clusters embedded into single and di-vacancy graphene

Structural, electronic and magnetic properties of 3d transition metal tetraoxide TMO 4 superhalogen clusters doped single vacancy (SV) and divacancy (DV) monolayer graphene have been studied using first-principles calculations. We found that in both cases of TMO 4 cluster substitution, all the impurity atoms are tightly bonded with graphene, having significant formation energy and large charge transfer occurs from graphene to TMO 4 clusters. CrO 4 and MnO 4 substituted SV graphene structures exhibit dilute magnetic semiconductor behavior in their spin down channel with 2.15 μ B and 3.51 μ B magnetic moment, respectively. However, CoO 4 , FeO 4 , TiO 4 and NiO 4 substitution into SV graphene, leads to Fermi level shifting to conduction band, thereby causing the Dirac cone to move into valence band and a band gap appears at high symmetric K -point. Interestingly, CoO 4 , CrO 4 , FeO 4 and MnO 4 substituted DV graphene structures exhibit dilute magnetic semiconductor behavior in their spin up channel with 1.74 μ B , 3.27 μ B , 3.09 μ B and 1.99 μ B magnetic moment, respectively. Detailed analysis of density of states (DOS) plots show that d orbitals of 3d TM atoms should be responsible for inducing magnetic moments in graphene. We believe that our results are appropriate for experimental exploration and graphene-based spintronic and magnetic storage devices.