Adsorption Of 3d Transition Metal Atoms Research Articles

Adsorption of 3d transition-metal atoms on two-dimensional penta-graphene: A first-principles study

The adsorption of single 3d transition metal (TM) atoms (from Sc to Zn) on a (3 × 3) penta-graphene (PG) sheet has been systematically studied by means of density-functional theory calculations. We particularly study the effect of the TM adatom on the structural, electronic, and magnetic properties when adsorbed on the PG sheet. Our calculations have shown that most of the TM adatoms are preferably adsorbed on the T2 site (i.e., the top of the C2 atom located at the bottom layer), while Cr, Zn, and Ni are preferably adsorbed on different B sites. The calculated band structures demonstrate that all TM-PG systems remain semiconductors such that the gap between the valence and conduction bands moves to a lower energy state relative to the Fermi level. For this reason, an apparent narrowing in the band gap values for the TM-PG systems has been predicted (0.11 – 0.97 eV) compared to the band gap of the isolated PG sheet (2.23 eV). Additionally, our results indicate that most of the TM-PG systems are magnetic, with the exception of Ni-PG and Zn-PG systems. Consequently, the engineering of the electronic properties of the TM-PG systems implies that such systems might be promising candidates for different applications.

Coexistence of magnetism in SnX (X = S, Se, Te) monolayers by the adsorption of 3d transition-metal atoms

Magnetism can be induced in two-dimensional (2D) group IV monochalcogenide monolayers (MLs) by the decoration of transition-metal (TM) atoms. The induced magnetism in the group IV monochalcogenides enhances their potentiality in 2D spintronic devices, which has attracted extensive attention nowadays. In this context, the structural, electronic, and magnetic properties of transition metal atoms (Mn, Fe, Co) adsorbed SnX (X = S, Se, Te) MLs are investigated by using first-principles calculations. The TM atoms adsorbed SnX MLs are found to be energetically stable with the pnma space-group, and show the semiconducting nature with electronic band gaps in the range of 0.52–1.05 eV revealing the negligible spin–orbit coupling effect in most of the studied systems. The asymmetry between spin majority and spin minority channels is revealed in the electronic density of states of the adsorbed systems, which is mainly contributed by the hybridization of the 3d orbitals of TM atoms with the 4p and 4s orbitals of Sn and X atoms. Magnetic states are realized for SnX atoms in the adsorbed systems with the induced magnetic moments between −0.03 to −0.33 μB, which indicates the antiferromagnetic alignment between TM atoms and neighboring SnX atoms. Co adsorbed SnSe and Fe adsorbed SnTe MLs are found to have significant magneto-crystalline anisotropy energy values of 0.37 and 0.84 meV/TM atom, respectively, with the preferred perpendicular direction. In addition, the p-type doping is induced in the SnX MLs as indicated by the calculation of charge transfer between the adsorbed TM and SnX atoms. The results demonstrate potential applications of TM atoms adsorbed SnX MLs for spintronic and magnetic storage devices.

Electronic and magnetic properties of MoS2 monolayers with antisite defects

The electronic and magnetic characteristics of MoS2 monolayers with antisite defects were investigated based on the density functional theory. For antisite defects, we refer to a single Mo atom substituting one S atom (MoS) and one Mo atom substituting two S atoms (MoS2). The mid-gap states were induced by antisite defects in the band structures of the MoS2 monolayer. The total magnetic moment of 2 μB was obtained in MoS and MoS2 systems. Adsorption of 3d transition metal (TM) atoms onto MoS and MoS2 monolayers was also investigated. Stable geometrical structures, adsorption energies, charge transfer, and magnetism were assessed. Large adsorption energies were acquired from these systems, except for those containing Zn atoms. Bader charge analysis revealed charge transfer from 3d TM atoms to the substrate, achieving the n-doping in MoS and MoS2 systems. Adsorption of 3d TM atoms dramatically influenced magnetism of these systems. Our results highlight the potential of these systems for TM-adsorbed MoS2 utilization in the future.

Tuning the electronic and magnetic properties of borophene by 3d transition-metal atom adsorption

The electronic and magnetic properties of borophene functionalized by 3d transition metal (TM) atom adsorption are investigated by using first-principles calculations. The results show that the 3d TM atoms can be adsorbed on borophene with high binding energies ranging between 5.9 and 8.3 eV. Interestingly, the originally nonmagnetic borophene tends to be ferromagnetic when Ti, V, Cr, Mn, and Fe atoms are adsorbed, and the magnetic moments are dominated by the TM atoms. The origin of the ferromagnetism is discussed based on the Stoner criterion. Our results indicate that the magnetic properties of borophene can be effectively tuned through the adsorption of 3d TM atoms, which could have promising applications in spintronics and nanoelectronics.