Adsorption of rare-earth atoms onl silicon carbide nanotube: a density-functional study

Abstract

In this paper, we investigate the adsorption of a series of rare-earth (RE) metal atoms ( La , Pr , Nd , Sm and Eu ) on the pristine zigzag (8, 0) silicon carbide nanotube ( SiCNT ) using density functional theory (DFT). Main focuses are placed on the stable adsorption sites, the corresponding binding energies, and the modified electronic properties of the SiC nanotubes due to the adsorbates. A single RE atom prefers to adsorb strongly at the hollow site with relatively high binding energy (larger than 1.0 eV). Due to the rolling effect of single-walled SiCNTs , the inside configurations are more stable than the outside ones. For RE-adsorbed systems, the adsorption of metal atoms induces certain impurity states within the band gap of the pristine SiCNT . Furthermore, we analyze there exists hybridizations between RE-5d, 6s, C -2p and Si -3p orbitals for the RE atom adsorption on the SiCNTs .