Magnetism of elemental two-dimensional metals

Abstract

Two-dimensional (2D) elemental metals have attracted considerable attention because of their fascinating physical properties and potential diverse applications. Information on the structures, mechanical properties, and dynamical stabilities of single atom thick phases of metallic elements in the periodic table has been previously reported. Here, the magnetic properties of 45 2D metals in three lattice structures (hexagonal, square, and honeycomb) were systematically explored using density functional theory calculations. Although it is well known that there are only five magnetic elements in their 3D counterparts, it is interesting to find that 18 of the 45 2D elemental metals are endowed with magnetism due to coordination number decreases and energy band narrowing of the out-of-plane orbitals. In particular, the honeycomb lattice is more likely to be magnetic than the square lattice. Most of the magnetic 2D metals are ferromagnetic and only a few are anti-ferromagnetic. It is further shown that the 2D metals with higher structural symmetry have smaller magnetic moments. These results provide a foundation for the further study of their magnetic/spintronic properties and their potential applications, such as in catalysis and gas sensing.