Room-Temperature Ordered Spin Structures in Cluster-Assembled Single V@Si₁₂ Sheets

Abstract

Since most of the existing pristine two-dimensional (2D) materials are either intrinsically nonmagnetic or magnetic with small magnetic moment per unit cell and weak strength of magnetic coupling, introducing transition metal atoms in various nanosheets has been widely used for achieving a desired 2D magnetic material. However, the problem of surface clustering for the doped transition metal atoms is still challenging. Here we demonstrate via first-principles calculations that the recently experimentally characterized endohedral silicon cage V@Si12 clusters can construct two types of single cluster sheets exhibiting hexagonal porous or honeycomb-like framework with regularly and separately distributed V atoms. For the ground state of these two sheets, the preferred magnetic coupling is found to be ferromagnetic due to a free-electron-mediated mechanism. By using external strain, the magnetic moments and strength of magnetic coupling for these two sheets can be deliberately tuned, which would be propitious to their advanced applications. More attractively, our first-principles molecular dynamics simulations show that both the structure and strength of ferromagnetic coupling for the pristine porous sheet are stable enough to survive at room temperature. The insights obtained in this work highlight a new avenue to achieve 2D silicon-based spintronics nanomaterials.

Metal-free Ternary BCN Nanosheets with Synergetic Effect of Band Gap Engineering and Magnetic Properties

“…As primary doping elements for the origin of magnetism, the introduced TM atoms tend to cluster with each other because of the strong d-d interactions, which results in inhomogeneous distribution of the TM atoms 16 , 17 . To date, research on TM elements doped BNNSs is limited to theoretical calculation 18 , 19 .…”

DFT Investigations on the Boron–Phosphorus Assembled Nanowires

“…For instance, a new family of M 12 N 12 (M=Al and Ga) cluster-assembled low-density materials based on state-of-the-art first-principles calculations were investigated, which are promising for molecular sieving, gas storage, and particularly, atomic transport, control and purification applications [28]. The assembled one-dimensional (1D) V 1 @Si 12 -NW-rI is reported to have good stability and be an antiferromagnetic semiconductor [29], which is different to the ferromagnetic metallic feature of the assembled 2D sheets [30]. Recently, we theoretically designed 1D P 10 [31] and P 8 N 2 nanowires (NWs) [32] were based on cluster assembly approach, both NWs have very good stability, and transition metal addatoms will introduce structural transition to sandwich chains and semiconductor-to-magnetic half-metal conversion.…”

Theoretical prediction of stable cluster-assembled CdSe bilayer and its functionalization with Co and Cr adatoms

“…We speculate that such materials can facilitate a number of potential functionalities that can be readily engineered. Earlier such attempts were made by Liu et al in their studies of cluster-assembled sheets of endohedrally doped Si 12 clusters with vanadium atoms 6 . They observed that two different types of cluster-assembled sheets prefer ferromagnetic ordering with free-electron-mediated mechanism.…”