Tunable ferromagnetism in assembled two dimensional triangular graphene nanoflakes

Abstract

Triangular graphene nanoflakes (TGFs), due to their novel magnetic configurations, can serve as building blocks to design new magnetic materials. Based on spin polarized density functional theory, we show that the two dimensional (2D) structures composed of zigzag-edged TGFs linked by 1,3,5-benzenetriyl units (TGF(N)-C(6)H(3)) are ferromagnetic. Their magnetic moments can be tuned by changing the size and edge termination of TGFs, namely magnetic moments increase linearly with the size of TGFs, and double hydrogenation of the edge carbon atoms can significantly enhance stability of the ferromagnetic states. The dynamic stability of the assembled 2D structures is further confirmed by frequency calculations. The characteristic breathing mode is identified where the frequency changes with the inverse square root of the TGFs width, which can be used to identify the size of TGF(N)-C(6)H(3) in Raman experiments. This study provides new pathways to assemble 2D ferromagnetic carbon materials.

Nitrogen-doping induces tunable magnetism in ReS2

“…To better comprehend the unique magnetic behavior of Ndoped ReS 2 , spin-polarized density functional calculations (DFT) were performed in the Vienna ab initio simulation package (VASP). 14,[32][33][34] To figure out the correlation between doping contents and magnetic distribution, the magnetic moment and charge distribution of the supercell comprised of 48 atoms had been presented in Fig. 5.…”

Ground-state magnetic phase diagram of bow-tie graphene nanoflakes in external magnetic field

“…In the context of intriguing magnetic characteristics, various graphene-based nanostructures are invoked, mainly to mention graphene nanoflakes (GNFs) or quantum dots, for which the ability of shaping the edge and designing the electronic structure allows to reach desirable properties . Numerous applications of these zero-dimensional graphene-based structures within an emerging field of spin electronics are suggested in the recent theoretical works [9][10][11][12]19,21,[29][30][31][32][33][34][35][36] . Among various graphene nanoflakes, particularly those of triangular shape and zigzag edge seem promising and attract the attention 19,[22][23][24][25]27,28,32,[37][38][39][40][41] .…”

Sulfur Doping Induces Strong Ferromagnetic Ordering in Graphene: Effect of Concentration and Substitution Mechanism

“…To gain a deeper understanding of the unique magnetic behavior of S‐doped graphenes, spin‐polarized density‐functional calculations were performed as theoretical methods based on density functional theory provide valuable information about the magnetic properties of graphene‐based structures . The substitutional doping was modeled by replacing carbon atoms in a graphene layer by sulfur atoms, considering doping concentrations between 1.0 and 14.6 at% at ≈1 at% (≈2 at%) intervals up to 4.2 at% (beyond 4.2 at%).…”