Theoretical Investigation of Structural and Electronic Properties of C_20Li Nanowire

We investigated electronic and structural properties of $$\hbox {C}_{{20}}\hbox {Li}$$ nanowire by first-principle calculations. The optimum adsorption position of Li on $$\hbox {C}_{{20}}$$ was found to be the bridge position by comparing the total energies of the adsorbed structures. We constructed $$\hbox {C}_{{20}}\hbox {Li}$$ nanowire by using Li adsorbed on $$\hbox {C}_{{20}}$$ at the bridge position as the building block. The nanowire has two local equilibriums at $$a_{\mathrm{eq}}=7.8$$ and 8.4 Å and shows ductile behavior under mechanical stress since the system utilizes all adsorption positions to relieve the strain. The on-top adsorption is observed in over-stretched nanowires while the pentagon site is preferred in over-compressed nanowires. In view of its flexible structure, $$\hbox {C}_{{20}}\hbox {Li}$$ may be incorporated in a matrix without inducing strain. The system is semiconductor with energy gap values $$E_g<1$$  eV for both $$a_{\mathrm{eq}}$$ equilibrium lattice values. Since the highest occupied band becomes unoccupied for minority spin, spin polarization of $$1{\mu }_B$$ per formula unit is observed. $$\hbox {C}_{{20}}\hbox {Li}$$ may be utilized as the building block of magnetic semiconductors.