Density functional theory investigation on cluster assembled Gd-encapsulated Si nanowires

Abstract

Two types of dimers constituted of two endohedral Gd@Si16 cages, Gd2@Si32 and Gd2@Si28, have been identified by employing the first-principle method. The geometries, stabilities, electronic and magnetic properties have been investigated. It can be learned that each of the embedded Gd atoms in Gd2@Si32 and Gd2@Si28 retains a large spin magnetic moment (MM) of about 7.0 μB, respectively, the total MM of Gd2@Si32 (2 μB) is far smaller than that of Gd2@Si28 (12 μB). Electronic structures analysis demonstrates that sp2-like hybridizations induced by the encapsulated Gd atoms arise in Si-Si bonds, which obviously stabilize the tube-like Si32 and Si28. In addition, two classes of assembled Si nanowires with Gd atoms encapsulation, Gd@SiNW-1 and Gd@SiNW-2, are gained, both of them are found to be metallic and have total MMs of 12 μB. All these structures may be potential candidates for applications in the spintronics and nano-magnetic storage devices.