Magnetic bipolarity of (8,0)SWCNT functionalized by methyl or light halomethyles

摘要

The geometrical, electronic and magnetic properties of (8,0)SWCNT, functionalized by either CH3, CH2F or CH2Cl form this treatise. We employ the density functional theory along with Grimme-D2 approach in spin polarization mode. From the calculated adsorption energies and distances, it is demonstrated that the adsorption of the radicals by (8,0)SWCNT is of chemisorption and exothermic nature. In the adsorption process, spin-down electrons migrate from (8,0)SWCNT to the radicals, giving rise to an exchange splitting. The resulted spin-distinct band structure and densities of states show that the aforementioned compounds behave as bipolar ferromagnetic semiconductors. We, moreover, evaluate the spin-flip energy gaps that demonstrates switchablity of the generated spin-polarized currents. This value turns out to be the smallest for the substance (8,0)SWCNT plus CH2F. According to the range of Fermi energy, for which a substance remains half-metal, it is concluded again that, the manipulation of spin states in compound (8,0)SWCNT plus CH2F is easier when used in the development of spintronic devices. Finally, we also present the compensation temperatures, below which the three substances remain ferromagnetic, indicating that the latter compound is operational up to 231.9 K. The present article, thus provides strong motivation for employing (8,0)SWCNT functionalized by CH2F in spintronic applications.