Localized magnetic moment induced by boron adatoms chemisorbed on graphene

Abstract

Inducing local spin-polarization in pristine graphene is highly desirable and recent experiment shows that boron adatom chemical attachment to graphene exhibits local high spin state. Using hybrid exchange-correlation functional, we show that boron (B) monomer chemisorbed on the bridge site of graphene is energically favorable, and indeed induces a weak local spin-polarization ~0.56 μB. The localized magnetic moment can be attributed to the charge transfer from boron atom to graphene, resulting in local spin charge dominantly surrounding to the adsorbed B and neighboring carbon (C) atoms. We also surprisingly find that boron dimer can even much more stable upright anchor the same site of graphene, giving rise to sizable spin magnetic moment 2.00 μB. Although the apparent spin state remains mainly contributed by B p and C p orbitals as the case of boron monomer, the delicate and substantial charge transfer of the intra-dimer plays a fundamental role in producing such sizable local spin-polarization. We employed various van der Waals corrections to check and confirm the validity of appeared local spin-polarization. In terms of the almost identical simulated scanning tunneling microscope between boron monomer and dimer, we might tend to support the fact that boron dimer can also be chemisorbed on graphene with much larger and stable localized spin magnetic moment.

Enhancing the energetic and magnetic stability of atomic hydrogen chemisorbed on graphene using (non)compensated B–N pairs

“…DFT-D3 method of Grimme vdW correction is employed to deal with the vdW interactions between the adsorbates and graphene as well as the graphene interlayers, 58 whose validity in a nonmetal atom adsorbed system has been confirmed in our previous work. 14…”

“…1–9 Integrating the high mobility and underlying magnetism of Dirac electrons into graphene becomes unprecedently desirable because magnetic/magnetized graphene is considered a highly promising candidate for future spintronic devices. 10–14 Nevertheless, intrinsic graphene is nonmagnetic owing to the π-conjugated electron system. 15 A well-known paradigm that needs to remove different numbers of p z orbitals from different triangular sublattices of graphene has been proposed by Lieb.…”

“…51,52 In both magnetic systems, characteristic splits of resonance peaks were clearly substantiated in the vicinity of the Fermi level, giving rise to sizable 1.0 μ B and higher 3.0 μ B for H and B atoms, respectively. However, for the B adsorbate, both high and weak spin polarizations are highly possible due to different functionals and van der Waals (vdW) interactions as well as different adsorbates, 14,53 while for the atomic H, the induced atomic scale magnetic moment is robust. Despite all these great advantages, the corresponding adsorption energy ( E a ) of H atoms chemisorbed on pristine graphene (H/G) is somewhat relatively small, −0.8 to −0.9 eV per atom.…”

Hole-Doped Nonvolatile and Electrically Controllable Magnetism in van der Waals Ferroelectric Heterostructures

“…Since the experimental preparation of intrinsic two-dimensional (2D) magnetic materials, such as Cr2Ge2Te6, [1] CrI3, [2] Fe3GeTe2, [3] and VSe2, [4] tuning ferromagnetism (FM) in 2D systems by an electric field has been an intriguing long-term goal in materials research [5][6][7][8] that still faces enormous challenges. For example, electric modulation of magnetic properties usually requires an ultra-strong electric field which is hardly met by the usual gate electrodes.…”