Atomic carbon growth on yttrium clusters: Relativistic density functional theory investigations

Abstract

The geometries, stabilities, and electromagnetic characteristics of CYn (n=1–14) clusters have been systematically investigated using relativistic density functional theory with the generalized gradient approximation. The growth process of CYn (n=1–14) clusters can be divided into three phases. First, the C atom replaces a surface atom of Yn+1 cluster when n<6. For the cluster with n=6, the C atom goes into the center of a tetragonal bipyramid and the C@Y6 cluster is formed. Over the range from n=7 to 14, Y atoms are successively capped onto the C@Y6 sub-cluster. Due to the C doping, the stability of clusters is enhanced and the magnetic moments are reduced compared to the corresponding pure yttrium clusters. In particular, doping with a carbon atom whether at the surface or in the subsurface can make some clusters transition from an open electronic shell to a closed electron shell.