Density Functional Investigation of Transition-Metal-Encapsulated SinCn (n = 7−10) Cagelike Clusters

Abstract

The geometries, stabilities, and electronic and magnetic properties of 3d and 4d transition-metal (TM)-encapsulated SinCn (n = 7−10) cagelike clusters are systematically investigated using the density functional theory with generalized gradient approximation. SinCn cagelike structures doped with TM atoms are stable, especially when they encapsulate 3d (or 4d) TM atoms. The formation of an endohedral structure strongly depends on the TM atom present and the SinCn cage size. Among the SinCn cages studied, the Si8C8 cage is the energetically optimal cage for encapsulating most of the 3d and 4d TM atoms. For TM@Si8C8, 3d and 4d TM dopants exhibit similar electronic and magnetic behaviors. The electronic properties of the TM@Si8C8 clusters are characterized by electron transfer from silicon and carbon atoms to TM atoms. The total magnetic moments of TM@Si8C8 clusters oscillate from 0 to 1 μB across the periodic table. The total magnetic moments are mainly located on the 3s and 3p states of Si atoms, and the 2p states of C atoms and TM atoms contribute the least.