Tunable Magnetism in Transition-Metal-Decorated Phosphorene

Abstract

We present a density functional theory study of 3d transition-metal (TM) atoms (Sc–Zn) adsorbed on a phosphorene sheet. We show that due to the existence of lone pair electrons on P atoms in phosphorene, all the TM atoms, except the closed-shell Zn atom, can bond strongly to the phosphorene with sizable binding energies. Moreover, the TM@phosphorene systems for TM from Sc to Co exhibit interesting magnetic properties, which arise from the exchange splitting of the TM 3d orbitals. We also find that strain is an effective way to control the magnetism of TM@phosphorene systems by tuning the interaction of the TM with phosphorene and, thus, the relative positions of in-gap TM 3d orbitals. In particular, a small biaxial strain could induce a magnetic transition from a low-spin to a high-spin state in phosphorene decorated by Sc, V, or Mn. These results clearly establish the potential for phosphorene utilization in innovative spintronic devices.

Half-Metallic Ferromagnetism and Surface Functionalization-Induced Metal–Insulator Transition in Graphene-like Two-Dimensional Cr2C Crystals

“…Thus the pursuit of tunable magnetism in 2D crystals has been a persisting goal for a long time [5][6][7][8] . In graphene and monolayer transition metal dichalcogenides, several ideas have been proposed to induce the magnetic moments and orderings, such as depositing magnetic adatoms on the surface [9][10][11] and introducing specific defects 5,6 or edges [12][13][14] . However, the experimental realization remains challenging: for example, the clustering of the adatoms is always inevitable 15 , and the edge morphology and defect type are not well controllable 16 .…”

Electronic structure of charged bilayer and trilayer phosphorene

“…How the electronic structure changes with the number of layers 11,12 , stacking order 13,14 , strength of an applied electric field [10][11][12][13]15,16 and strain 17 has been extensively studied. The effects of various transition metal dopants have also been investigated [18][19][20][21][22] . The possibility of electrondoped phosphorene being a superconductor above liquidhelium temperature was considered 23 .…”

Magnetic 3d Transition Metal Atomic Chains Modulated by the Intrinsic Valley Structure in MX Monolayer

“…[28] For most of 3d TM atoms, the adsorption energies are in the range of 1.54-4.86 eV, which are very sizable. The overall trend of adsorption energies follows the shape of double peaks as a function of the number of d electrons, which is similar to that of TM-phosphorene.…”

“…The overall trend of adsorption energies follows the shape of double peaks as a function of the number of d electrons, which is similar to that of TM-phosphorene. [28,32] For example, the adsorption energy of Mn on graphene is only 0.42 eV, but it is about 1.51 eV on the topological line defect of graphene, and around 2.0 eV on phosphorene, as shown in Table S1 (Supporting Information) According to our calculations, the adsorption energy of Mn on monolayer SiAs, GeAs, SiP and GeP increase to 1.73, 1.81, 2.14, and 2.13 eV, respectively. While Zn adatom has a rather small adsorption energy of about 0.37-0.41 eV due to its full-filled d shell.…”

“…In a word, the adsorption energies suggest that most 3d TMs can be strongly adsorbed on the bridge site over the (MM) x in the intrinsic valley of the single layer MX apart from Zn atom. [28] The high reactivities of carbon atoms in the topological line defect with octagonal and pentagonal rings enhances the TMs bonding, which increases the adsorption energy of Mn from 0.42 to 1.51 eV. [28,32] For example, the adsorption energy of Mn on graphene is only 0.42 eV, but it is about 1.51 eV on the topological line defect of graphene, and around 2.0 eV on phosphorene, as shown in Table S1 (Supporting Information) According to our calculations, the adsorption energy of Mn on monolayer SiAs, GeAs, SiP and GeP increase to 1.73, 1.81, 2.14, and 2.13 eV, respectively.…”