Prediction of Two-Dimensional Janus Transition-Metal Chalcogenides: Robust Ferromagnetic Semiconductor with High Curie Temperature.

Two-dimensional (2D) ferromagnetic semiconductors (FM SCs) provide an ideal platform for the development of quantum information technology in nanoscale devices. However, many developed 2D FM materials present a very low Curie temperature (T), greatly limiting their application in spintronic devices. In this work, we predict two stable 2D transition metal chalcogenides, VSeX (X = S, Te) monolayers, by using first-principles calculations.

Ab Initio Study of Structural, Electronic and Magnetic Properties of TM&(B@C) (TM = V, Cr) Sandwich Clusters and Infinite Molecular Wires.

The geometrical structure, electronic and magnetic properties of B-endoped C (B@C) ligand sandwich clusters, TM&(B@C) (TM = V, Cr), and their one-dimensional (1D) infinite molecular wires, [TM&(B@C)], have been systematically studied using first-principles calculations. The calculations showed that the TM atoms can bond strongly to the pentagonal (η-coordinated) or hexagonal rings (η-coordinated) of the endoped C ligands, with binding energies ranging from 1.90 to 3.

Structural Evolution of Boron Clusters on Ag(111) Surfaces - From Atomic Chains to Triangular Sheets with Hexagonal Holes.

Unlike graphene and other 2D materials, borophene is 2D polymorphic with diverse hexagonal holes (HHs)-triangles ratios and the concentrations of HHs are highly substrate dependent. Here, we systematically explored the evolution of boron cluster on Ag(111) surface, B @Ag(111) (N=1∼36), to understand the nucleation of 2D boron sheet on metal surface. Our calculation showed that, with the size increasing, the structures of most stable B clusters undergo an evolution from compact triangular lattice, such as double-chains or triple-chains, to the ones with mixed triangular-hexagonal lattices.