The Manganese Doping Of BN Sheet

Analogue to graphene, BN sheet, a wide gap semiconductor, has beensuccessfully fabricated in experiments. BN sheet has aroused extensive researchinterest due to its many intriguing properties such as high chemical stabilities,excellent mechanical properties, and high thermal conductivities. The electronic andmagnetic properties of BN sheets can be effectively modulated by the existence oftransition-metal (TM). In present work, we systematically study electronic andmagnetic properties of BN sheet with TM atoms adsorption. The correspondingresults as follows.(1) We study the adsorption energy, electronic structures and magnetic propertiesof single TM (V, Cr, Mn, Fe, Co and Ni) adsorbed on BN sheet based on both LSDAand GGA. We find that the stable adsorption configuration and adsorption typedepend on the choice of the exchange–correlation functional (GGA or LDA), whichderives from the over-binding shortcoming of LDA. In view of the well-knownover-binding shortcoming of LSDA, the choice of the exchange–correlationfunctional is important for theoretical predication of the TM adsorbed BN sheet basedon first-principles method. Our results indicate that3d TM can adsorb on the BNsheet stably and some systems show magnetism. Furthermore, for V, Cr, Mn, Fe andCo adsorbed BN sheet, the spin polarization is found to be100%at Fermi level or thehighest occupied molecular orbital (HOMO), which can be used as potentialspin-filtering material in spintronics.(2) We study the geometries, magnetic and electronic properties of thehetero-dimer (NiV, NiCr, NiMn, NiFe and NiCo) adsorbed on BN sheet. Our resultsshow that the adsorption energies are largely lower than that of single adatom cases.The most stable configurations for hetero-dimer is that dimer bond axis is nearlyperpendicular to BN sheet at different sites. Both NiV and NiCr dimers areanti-ferromagnetic coupling. Whereas NiMn, NiFe and NiCo dimers areferromagnetic coupling. Additionally, we observed that100%spin polarization occursthe Fermi level or HOMO level for these hetero-dimer adsorbed on BN sheet, whichcan be served as potential materials for spintronics.(3) We study the geometries, magnetic and electronic properties of thehomonuclear dimers (VV, CrCr, MnMn, FeFe, CoCo and NiNi) adsorbed on BNsheet. We observed that100%spin polarization can be achieved at the Fermi level or HOMO level for CoCo, MnMn and FeFe homo-dimer adsorbed on BN sheet, whichcan be served as potential materials for spintronics. Furthermore, we found that theadsorbed CrCr dimer is anti-ferromagnetic, while VV, CrCr and MnMn dimers areferromagnetic.(4) We study the geometries, magnetic and electronic properties of the small Nicluster adsorbed on BN sheet. Our results show that Ni dimer and Ni trimeradsorption systems reached100%spin polarization at the Fermi level, respectively.