Unexpected strong magnetism of Cu doped single-layer MoS₂ and its origin

Abstract

The magnetism of the 3d transition-metal (TM) doped single-layer (1L) MoS2, where the Mo atom is partially replaced by the 3d TM atom, is investigated using the first-principles density functional calculations. In a series of 3d TM doped 1L-MoS2's, the induced spin polarizations are negligible for Sc, Ti, and Cr dopings, while the induced spin polarizations are confirmed for V, Mn, Fe, Co, Ni, Cu, and Zn dopings and the systems become magnetic. Especially, the Cu doped system shows unexpectedly strong magnetism although Cu is nonmagnetic in its bulk state. The driving force is found to be a strong hybridization between Cu 3d states and 3p states of neighboring S, which results in an extreme unbalanced spin-population in the spin-split impurity bands near the Fermi level. Finally, we also discuss further issues of the Cu induced magnetism of 1L-MoS2 such as investigation of additional charge states, the Cu doping at the S site instead of the Mo site, and the Cu adatom on the layer (i.e., 1L-MoS2).

Electronic structures and magnetic properties in nonmetallic element substituted MoS2 monolayer

“…Actually, 2D MoS 2 ferromagnetic (FM) materials have been heralded as ideal candidates for the dilute magnetic semiconductors, which can exploit both the charge and spin degrees of freedom of the electron in one device [18], yielding remarkable properties and functionalities, in the field of spintronics. Besides the various magnetic properties induced by doping transition-metal [8][9][10][11][12][13]19,20], the adsorption of adatoms at the 2D monolayer MoS 2 have crucial effects on the electronic and magnetic properties [21,22]. The large spatial extensions of spin density and long-range antiferromagnetic (AFM) coupling were observed in H-and F-absorbed MoS 2 monolayers.…”

“…More recently, it has been demonstrated that valley polarization can be induced and controlled by using a circularly polarized light or by a magnetically doping in single-layer MoS 2 [7,8]. Diverse magnetic orderings have been reported recently in transition-metal-doped including Mn, Fe, Cu-doped MoS 2 [9][10][11][12][13]. Consequently, monolayer MoS 2 is a promising material for ''valleytronics'', spintronics, and nanoelectronic devices.…”

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

“…6,7 Furthermore MoS 2 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 MoS 2 . [10][11][12][13][14] These studies verified that the electronic and magnetic properties of MoS 2 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 MoS 2 monolayer structurally and electronically, the WS 2 monolayer has special electronic and magnetic characteristics and attracted more and more attention.…”

Electronic structures and magnetic properties in Cu-doped two-dimensional dichalcogenides

“…Theoretical works have reported that diverse magnetic orderings can be realized in transition-metal-doped MX2 [11][12][13][14][15][16][17][18][19]. Based on density functional theory, Feng et al have shown that Fe-terminated Fe4N in contact with monolayer MoS2 has potential in spintronics devices, [20] and Zhang et al have predicted that the contact between monolayer MoS2 and Gd(0001) can be used to realize good spin injection [21].…”

“…Ferromagnetism with high Curie temperature has been realized in atomically thin MoS 2 and WS 2 nanosheets without magnetic ions [24]. Especially, the Cu doped MoS 2 shows unexpectedly strong magnetism although Cu is nonmagnetic in its bulk state, but the magnetic ground states is still undiscovered [15]. Therefore, it is timely to systematically study the magnetic properties of Cu-doped MoS 2 , MoSe 2 , MoTe 2 , and WS 2 systmes.…”