First-principles investigation on cluster-assembled silicon nanotubes with Eu atoms encapsulation.

Two kinds of dimers consisting of two endohedral Eu@Si cages, Eu@Si and Eu@Si, have been predicted by using density functional theory. The structural stabilities, electronic structures, and magnetic properties have been examined at the DFT-GGA level. The results show that each of the central Eu atoms in Eu@Si and Eu@Si keeps spin magnetic moment of about 6.9 μ, respectively. Analysis of electronic structures shows that sp-like hybridizations induced by the central Eu atoms arise in Si-Si bonds, which remarkably improve the stabilities of both Si and Si clusters. Furthermore, two types of assembled Si nanotubes (Eu@SiNT-1 and Eu@SiNT-2) with Eu atoms encapsulated are gained; it is found that both of them are of metallic conductive character and have total magnetic moment of 14 μ. All these structures may be rather tempting for the future spintronic devices and high-density magnetic storage materials. Graphical abstract The electronic and magnetic properties of cluster-assembled Eu@SiNTs.