Density Functional Study of Fluorinated Single-Walled Silicon Carbide Nanotubes

Structural, electronic, and magnetic properties of fluorine (F)-doped silicon carbide nanotubes (SiCNTs) are studied using density functional theory. It is found that F atoms prefer to adsorb on Si sites of both (8, 0) and (6, 6) SiCNTs. The chemisorption of the F atom on the Si site also induces a push down of the Fermi level for both types of SiCNTs, whereas the Fermi levels are lifted up when the F atom is attached on the C site of the tubes. Our calculation results show that fluorine adsorption for either a single silicon or a single carbon atom yields spontaneous magnetization, and the net magnetic moment is 1 µ_B. This may lead to a new approach to tune the electronic and magnetic properties of SiCNTs toward some nanoelectronics and metal-free magnetic materials.