Intrinsic Ferromagnetism in 2D Fe₂H with a High Curie Temperature

Abstract

The rational design of ferromagnetic materials is crucial for the development of spintronic devices. Using first-principles structural search calculations, we have identified 73 two-dimensional transition metal hydrides. Some of them show interesting magnetic properties, even when combined with the characteristics of the electrides. In particular, the P3̅m1 Fe2H monolayer is stabilized in a 1T-MoS2-type structure with a local magnetic moment of 3 μB per Fe atom, whose robust ferromagnetism is attributed to the exchange interaction between neighboring Fe atoms within and between sublayers, leading to a remarkably high Curie temperature of 340 K. On the other hand, it has a large magnetic anisotropic energy and spin-polarization ratio. Interestingly, the above room-temperature ferromagnetism of the Fe2H monolayer is well preserved within a biaxial strain of 5%. The structure and electron property of surface-functionalized Fe2H are also explored. All of these interesting properties make the Fe2H monolayer an attractive candidate for spintronic nanodevices.

An antiferromagnetic semiconducting FeCN2monolayer with a large magnetic anisotropy and strong magnetic coupling

“…Iron (Fe), as a typical magnetic element, has aroused much interest in exploring 2D Fe-based magnetic materials. 15,17,26,27 For instance, two novel Fe 8 N monolayers, named H-Fe 8 N and B-Fe 8 N with distinguishable N atomic occupations, exhibit a lowspin state and a high-spin FM state, respectively. 28 In addition to the large magnetic moments, a room-temperature FM Fe 4 N 2 monolayer has been reported, as a nodal-loop half metal with a Curie-temperature (T c ) of about 428 K. 29 Besides these intriguing findings of Fe-based nitrides, 2D FeC 2 nanosheets, chemically exfoliated from bulk ThFeC 2 , have a high T c of 245 K. 30 An Fe 2 C monolayer with a T-phase atomic structure exhibits a roomtemperature AFM order.…”

Polydopamine‐assisted in situ formation of dense aramid nanofibers layer on polyethylene separator for lithium‐ion battery

“…Although irradiation grafting (such as electron beam irradiation grafting, 17 plasma grafting, 18 UV grafting 19 ) can effectively enhance the hydrophilicity of the separator surface, it finally impair the mechanical performance of the separator during the irradiation process. Compared to the irradiation grafting strategy, coating method may be considered as a simple technology to obtain the uniform surface by using the multi‐component coating system with γ‐LiAlO 2 , 20 Al 2 O 3 , 21 MgO, 22 TiO 2 , 23 SiO 2 , 18 ZrO 2 24 . Although the nanoparticles have the positive effect to the thermostability and electrolyte wettability of the separator, the micropore of separators also be easily to blockage which may inhibit the migration of lithium‐ion and even the closely stacked of nano‐sized particles into the coating solution could lead to the less porosity on the surface of separators 25 .…”

Antiferromagnetic Fe3As nanostructure with a unique planar Fe arrangement

“…10–14 Thus far, the study of 2D magnetic materials has made breakthrough progress including an insight into the magnetic origins and the design of high-performance materials. 15,16 For instance, the itinerant ferromagnetism in substantial 2D metallic materials is explained by the Stoner criterion, 17–19 which is manifested as the competition between kinetic and exchange energy contributed by Coulomb repulsion. 20 The ferromagnetic (FM) coupling between the magnetic ions in 2D MnSiTe 3 originates from the interplay between the exchange coupling interaction and Ruderman–Kittel–Kasuya–Yosida interaction.…”