Air‐Stable 2D Intrinsic Ferromagnetic Ta₃FeS₆ with Four Months Durability

Abstract

2D ferromagnetic materials provide an important platform for the fundamental magnetic research at atomic-layer thickness which has great prospects for next-generation spintronic devices. However, the currently discovered 2D ferromagnetic materials (such as, CrI 3 , Cr 2 Ge 2 Te 6 , and Fe 3 GeTe 2) suffer from poor air stability, which hinders their practical application. Herein, intrinsic long-range ferromagnetic order in 2D Ta 3 FeS 6 is reported, which exhibits ultrahigh stability under the atmospheric environment. The intrinsic ferromagnetism of few-layer Ta 3 FeS 6 is revealed by polar magneto-optical Kerr effect measurement, which exhibits giant MOKE response and has Curie temperature of ≈80 K. More importantly, few-layer Ta 3 FeS 6 nanosheet exhibits excellent air stability and its ferromagnetism remains unchanged after 4 months of aging under the atmosphere. This work enriches the family of 2D ferromagnetic materials, which will facilitate the research progress of spintronics. 2D materials have generated great research interest due to their atomic flat interface structure, unique electronic structure (semiconducting, metallic, and superconducting), and a wide range of applications (high-mobility transistors, ultra-sensitive photodetectors, high-efficiency energy conversion). [1-6] The emerging 2D ferromagnetic materials combining spin with the unique electronic structure of 2D materials exhibit novel magnetoelectric and magneto-optical properties, which prefigures the rising of spintronics. [7,8] Recently, 2D ferromagnetism was discovered in chromium trihalides (CrX 3 , X = Cl, Br, I), [9-13]

Chiral Helimagnetism and One‐Dimensional Magnetic Solitons in a Cr‐Intercalated Transition Metal Dichalcogenide

“…[ 14 ] Similar to conventional vdW magnets, the intercalated TMDCs are cleavable and maintain long‐range magnetic order even down to 2D scale. [ 15–17 ] More importantly, if the intercalator concentration is precisely controlled at x = 1/3 in T x MX 2 (T = V, Cr, Mn, Fe, Co, Ni; M = Nb, Ta; X = S, Se), the entire system forms a noncentrosymmetric chiral crystal structure ( P 6 3 22 space group), although its parent compound MX 2 is centrosymmetric non‐chiral. [ 18 ] The amalgamation of long‐rang magnetic order and crystal chirality in T x MX 2 may promote interesting spin textures, such as magnetic solitons.…”

Recent Advances in 2D Group VB Transition Metal Chalcogenides

“…Ternary GVTMCs show more abundant magnetic states owing to their extra component freedom, such as hard ferromagnet Ta 3 FeS 6 , Ta 4 FeS 8 , chiral helimagnet Nb 3 CrS 6 , and spin glass NbFeTe 2 . [ 45,46,54,56,75–80 ] Morosan and co‐workers demonstrated the strong magnetic anisotropy in Ta 4 FeS 8 via anisotropic magnetotransport measurements. [ 80 ] They found that the magnetic moments of Ta 4 FeS 8 are parallelly aligned along the c ‐axis and exhibit sharp switching behavior under the out‐plane magnetic field with Curie temperature of 160 K. [ 80 ] Further, Park and co‐workers demonstrated the Ruderman–Kittel–Kasuya–Yosida magnetic coupling with Ising‐type spin states in Ta 4 FeS 8 .…”

“…[ 56 ] Recently, Zhai and co‐workers revealed the intrinsic ferromagnetism in 2D Ta 3 FeS 6 . [ 46 ] They found that the few‐layer Ta 3 FeS 6 shows giant magneto‐optical Kerr effect and ultrahigh air stability with 4 months durability. [ 46 ] More intriguing, chiral magnetic orders are observed in Nb 3 CrS 6 which has unique magnetic soliton lattice.…”

“…[ 46 ] They found that the few‐layer Ta 3 FeS 6 shows giant magneto‐optical Kerr effect and ultrahigh air stability with 4 months durability. [ 46 ] More intriguing, chiral magnetic orders are observed in Nb 3 CrS 6 which has unique magnetic soliton lattice. [ 78 ] Gai and co‐workers demonstrated the magnetic soliton phase transition in Nb 3 CrS 6 at different thickness.…”

“…[ 21,22 ] Also, the 2D GVTMCs become extremely sensitive to the surrounding stimulations, such as light, [ 127 ] gases, [ 39 ] biomolecules, [ 37 ] and chemical agents, [ 38 ] thus enabling the development of a variety of sensors with high specificity. Noteworthily, the ferromagnetism in 2D VS 2 , [ 23,152 ] VSe 2 , [ 24–27,69 ] and Ta 3 FeS 6 [ 46,102 ] has been demonstrated, making GVTMCs as the particularly attractive 2D magnetic materials for van der Waals spintronic applications.…”