Structural, electronic and magnetic properties of GdSin (n=1-17) clusters: A density functional study

The geometries, stabilities, electronic and magnetic properties of GdSin (n=1-17) clusters have been investigated systematically by using density functional theory (DFT) with the generalized gradient approximation (GGA). We find that the Gd atom in the lowest-energy configuration gradually moves from convex to surface, and to the interior site as the number of Si atom varies from 1 to 17. Furthermore, from GdSi16, Gd atom in GdSi16 cluster completely falls into the center of the Si framework and forms a fullerene cage. On the basis of the atomic average binding energy [Eb(n)], the second difference in energy (Δ2E) and VIP, we predict that the magic number of GdSin (n=1-17) clusters should be 5, 11 and 16, and these clusters should be abundant in the mass spectra when n=5, 11 and 16. The magnetic moments of the GdSin clusters are also studied. It is found that the total magnetic moments and the magnetic moments on Gd of GdSin clusters are large, and they do not quench when Gd is encapsulated in Si outer framework cage, which is to a large extent due to the fact that the Gd 4f electrons hardly interact with the silicon cage.