Electronic and magnetic properties of3dtransition-metal atom adsorbed graphene and graphene nanoribbons

Abstract

In this paper, we theoretically studied the electronic and magnetic properties of graphene and graphene nanoribbons functionalized by 3d transition-metal ͑TM͒ atoms. The binding energies and electronic and magnetic properties were investigated for the cases where TM atoms adsorbed to a single side and double sides of graphene. We found that 3d TM atoms can be adsorbed on graphene with binding energies ranging between 0.10 and 1.95 eV depending on their species and coverage density. Upon TM atom adsorption, graphene becomes a magnetic metal. TM atoms can also be adsorbed on graphene nanoribbons with armchair edge shapes ͑AGNR's͒. Binding of TM atoms to the edge hexagons of AGNR yields the minimum energy state for all TM atom species examined in this work and in all ribbon widths under consideration. Depending on the ribbon width and adsorbed TM atom species, AGNR, which is a nonmagnetic semiconductor, can either be a metal or a semiconductor with ferromagnetic or antiferromagnetic spin alignment. Interestingly, Fe or Ti adsorption makes certain AGNR's half-metallic with a 100% spin polarization at the Fermi level. Present results indicate that the properties of graphene and graphene nanoribbons can be strongly modified through the adsorption of 3d TM atoms.

Structural and electronic properties of the Ptn–PAH complex (n = 1, 2) from density functional calculations

“…There has also been focus on adsorption of metal clusters on graphene [9][10][11][12][13][14][15] . For example, adsorption of different metal adatoms on graphene has been studied 10 , electronic and magnetic properties of graphene functionalized by 3d transition-metal atoms have been investigated 12 , and electronic structures and magnetic properties of transition metal M (Fe, Co, Ni, and Cu) adatom and dimer adsorbed on graphene have been studied 11 .…”

“…In this regard, it is necessary to understand the microstructure of Pt/C to analyze the interaction between the Pt atoms and the carbon surface, and to investigate the stability of Pt nano-particles on carbon materials. There are several theoretical efforts devoted to an improved understanding of the Pt-C interaction [10][11][12][13][14][15][26][27][28][29][30][31][32][33][34][35][36][37] . Kong et al, investigated the single Pt-atom adsorption on a carbon nanotubes (CNTs) and graphite nano-fibers (GNFs) 27 , and observed strong adsorption on atomic vacant sites or graphene edges.…”

“…Howells and co-workers 40 investigated the influence of substrate defect sites on the morphology of Pt vapor deposited on the basal plane of HOPG by XPS and STM and indicated that the interaction between a Pt cluster and HOPG depends on the surface condition of HOPG. Density functional theory (DFT) has become an invaluable tool in studying the interaction between metal clusters and graphene at the atomic level [9][10][11][12][13][14][15] . However, when considering this type of interaction, the effect of dispersion forces becomes important, as for example in the adsorption of aromatic molecules on metal surfaces [41][42][43][44][45][46][47] .…”

Magnetic adatoms in two and four terminal graphene nanoribbons: A comparison between their spin polarized transport

“…Metal atoms adsorbed onto graphene sheets also represent a new way for the development of new electronic or spintronic devices. The electronic, structural, and magnetic properties of transition metals (TM) on graphene sheets [20][21][22] and graphene nanoribbons (GNR) [23][24][25][26] have been studied extensively, which are mostly based on abinitio density-functional theory (DFT). The spin dependent transport in GNRs in presence of Rashba SOC has been investigated in some cases, such as spin filtering effect in zigzag GNR 27 , possible spin polarization directions for GNR with Rashba SOC 28 , effects of spatial symmetry of GNR on spin polarized transport 29 etc.…”

“…Since the edges play an important role in determining the electronic properties of GNR, they offer a variety of possibilities for tunable electronic properties, such as edge modulation by inorganic atoms, molecules or radicals [13][14][15][16] , application of transverse electric fields 17 , adsorption or doping of atoms or molecules [18][19][20][21][22][23][24][25][26] etc. Metal atoms adsorbed onto graphene sheets also represent a new way for the development of new electronic or spintronic devices.…”