Tailoring Dzyaloshinskii–Moriya interaction in a transition metal dichalcogenide by dual-intercalation

Abstract

Dzyaloshinskii–Moriya interaction (DMI) is vital to form various chiral spin textures, novel behaviors of magnons and permits their potential applications in energy-efficient spintronic devices. Here, we realize a sizable bulk DMI in a transition metal dichalcogenide (TMD) 2H-TaS2 by intercalating Fe atoms, which form the chiral supercells with broken spatial inversion symmetry and also act as the source of magnetic orderings. Using a newly developed protonic gate technology, gate-controlled protons intercalation could further change the carrier density and intensely tune DMI via the Ruderman–Kittel–Kasuya–Yosida mechanism. The resultant giant topological Hall resistivity $${\rho }_{{xy}}^{T}$$ ρ x y T of $$1.41{\mathrm{\mu}} \Omega \cdot {{\mathrm{cm}}}$$ 1.41 μ Ω ⋅ cm at $${V}_{g}=-5.2{\mathrm{V}}$$ V g = − 5.2 V (about $$424 \%$$ 424 % larger than the zero-bias value) is larger than most known chiral magnets. Theoretical analysis indicates that such a large topological Hall effect originates from the two-dimensional Bloch-type chiral spin textures stabilized by DMI, while the large anomalous Hall effect comes from the gapped Dirac nodal lines by spin–orbit interaction. Dual-intercalation in 2H-TaS2 provides a model system to reveal the nature of DMI in the large family of TMDs and a promising way of gate tuning of DMI, which further enables an electrical control of the chiral spin textures and related electromagnetic phenomena.

Hard Ferromagnetism Down to the Thinnest Limit of Iron-Intercalated Tantalum Disulfide

“…Transition metal dichalcogenides (TMDs) intercalated with open-shell transition metals comprise a family of materials with inherently tunable MCA, which makes them appealing targets for realizing 2D magnets with deterministic properties. The strength of MCA in intercalated TMDs is determined by the respective magnitudes of spin–orbit coupling (SOC) and unquenched orbital angular momentum (OAM) of the spin-bearing ions. − While the SOC is increased when the host lattice or the intercalants comprise heavy elements, the OAM of spin-bearing ions is shaped by their oxidation states and coordination environments imposed by the interlayer galleries. − However, low-dimensional analogues of these systems have not been magnetically characterized; strong interlayer interactions in the effectively ionic, bulk crystals of these intercalation compounds have, so far, precluded exfoliation of pristine, large 2D flakes suited for magnetic studies. − Consequently, the manifold possibilities for designing a new class of 2D magnets with controllable MCA by exploiting the tunable vdW interface, host lattice, and intercalant identity/stoichiometry remain untapped.…”

Anisotropic Magnetoresistance Effect of Intercalated Ferromagnet FeTa3S6

“…Very large magnetoresistance (≈140%) is discovered in single crystal Fe 0.297 TaS 2 , attributed to the Fe concentration departure from 1/4 or 1/3, which caused misalignment of magnetic moments [27]. Recently, Dzyaloshinskii-Moriya interaction (DMI) confirmed in topological structures such as magnetic skyrmions was also confirmed in Fe 0.28 TaS 2 nanoplates; this shows a large topological Hall effect, which confirms the DMI in a transition metal dichalcogenide by dual intercalation [29][30][31][32]. In addition, the ferromagnet Fe x TaS 2 also exhibits many peculiar magnetic properties, such as sharp switching of magnetization [26], strong magnetocrystalline anisotropy [33], butterfly-shaped double-peak magnetoresistance [27], anomalous Hall effect [34], and anisotropic magnetoresistance effect [33].…”

“…For example, Cu or Pd intercalation induces superconductivity in 1T-TiSe 2 [18,19], and 3d transition metal intercalation leads to different kinds of long-range magnetic order in TMDs (such as TiS 2 ) [20]; among the compounds with Cr-intercalated NbS 2 , Cr 1/3 NbS 2 is a chiral helimagnet, which confirms the strong coupling between neighboring layers [21,22]. Fe x TaS 2 is a transition metal dichalcogenide of magnetic element intercalation 2H-TaS 2 , which exhibits abundant magnetic properties [23][24][25][26][27][28][29][30][31][32][33][34]. It is in the spin glass state for x < 0.2, ferromagnetic for 0.2 ≤ x ≤ 0.4, and antiferromagnetic for x > 0.4 [23,24].…”

Structure and Magnetism of Iron- and Chromium-Intercalated Niobium and Tantalum Disulfides

“…Another possible explanation for the differences in magnetic exchange in Fe x TaS 2 for x = 0.25 and 0.33 is the presence of some spin canting in the √ 3 × √ 3 superlattice. Even though deviation of spin alignment from the c axis would be unfavorable due to MCAE, some degree of canting away may be stabilized by: (1) DM interactions (Figure 5) arising from the breaking of inversion symmetry 61 in the √ 3× √ 3 supercell, or (2) an AFM component in the magnetic exchange, which could emerge from differences in the carrier densities 15,22,61 and intercalant spacings for the x = 0.33 structure compared to the x = 0.25 system. Regardless of the origin, spins canting away from the out-of-plane FM order could decrease T C , 12,62 potentially explaining differences in T C across the phase diagram.…”