Ab initio study of electronic and magnetic properties in Ni-doped WS2 monolayer

Min Luo,Shen Yu Hao,Yin Tai Ling

doi:10.1063/1.4961468

Abstract

The magnetic properties of Ni-doped WS2 monolayer are investigated using first-principles method. The results indicate that both one-Ni-doped and the nearest two-Ni-doped systems are magnetic. The p-d hybridization between the Ni atom and its neighboring S atoms results in the ferromagnetic interaction of the Ni-doped WS2 monolayer. The antiferromagnetic coupling is observed with increasing Ni-Ni distance which can be explained by two-impurity Haldane-Anderson model using quantum Monte Carlo method. Our studies show that the nearest two Ni-doped WS2 monolayers to be candidates for two-dimensional transition-metal nanosheets. Moreover, we discussed the differences in the formation energy between W-rich and S-rich conditions. Our results also predict that it would be easier to incorporate Ni atoms into a S-rich WS2 monolayer in the experiment.

Highlights

The antiferromagnetic coupling is observed with increasing Ni-Ni distance which can be explained by two-impurity Haldane-Anderson model using quantum Monte Carlo method
MoS2 materials are predicted to be very suitable for spintronics applications due to their specially well-defined spin-splitting property,[8,9] and diverse magnetic orderings have been reported theoretically in transition-metal (TM) doped MoS2.10–14 These studies verified that the electronic and magnetic properties of MoS2 materials can be modified by TM dopants, which may lead to a new class of thin dilute magnetic semiconductors (DMS) in the engineering field
We have performed first-principles calculations based on density functional theory (DFT) within the generalized gradient approximations (GGA-PBE)[21] as implemented in the VASP package.[22]

Summary

INTRODUCTION

Two-dimensional (2D) transition-metal materials have been widely studied owing to their intriguing electronic, optical, chemical and mechanical properties.[1,2,3,4,5] Among them, the MoS2 nanosheets have attracted great interest, MoS2-based nano scaled semiconductor devices have been successfully fabricated.[6,7] MoS2 materials are predicted to be very suitable for spintronics applications due to their specially well-defined spin-splitting property,[8,9] and diverse magnetic orderings have been reported theoretically in transition-metal (TM) doped MoS2.10–14 These studies verified that the electronic and magnetic properties of MoS2 materials can be modified by TM dopants, which may lead to a new class of thin dilute magnetic semiconductors (DMS) in the engineering field. Be similar with MoS2 monolayer structurally and electronically, the WS2 monolayer has special electronic and magnetic characteristics and attracted more and more attention.[15,16,17,18] the pure WS2 monolayer is nonmagnetic. It is of interest to investigate the magnetic properties of Ni doped WS2. We studied the electronic and magnetic properties of Ni-doped WS2 monolayer with different Ni concentrations by the first-principles calculations. For two-Ni-doped monolayers of different configurations, the local magnetic moment disappears while the NiNi distance increases. Our results predict that it is easier to incorporate Ni atoms into a S-rich WS2 monolayer in the experiment

CALCULATION DETAILS

RESULTS AND DISCUSSION

CONCLUSION