Two-Dimensional Lattices of VN: Emergence of Ferromagnetism and Half-Metallicity on Nanoscale

Abstract

Two-dimensional (2D) ferromagnets with high spin-polarization ratio and high Curie temperature are crucial for developing next-generation spintronic nanodevices. Using first-principles calculations, we predict two polymorphic modifications ( t-VN and h-VN) of 2D VN lattices that have robust intrinsic ferromagnetic properties and high Curie temperatures. Whereas t-VN has 99.9% of spin polarization at the Fermi level, h-VN possesses a half-metallic type of conductivity and keeps it after contact with semiconducting MoS, which can be used as the substrate for h-VN synthesis and valley polarized contacts. Magnetocrystalline anisotropy energy of 2D VN polymorphs is found to be at least an order larger than those of Fe and Ni bulks. The phonon spectra and ab initio molecular dynamic simulation prove that 2D VN lattices have a high thermodynamic stability. These advantages demonstrate that the VN monolayers should be promising candidates for low-dimensional spintronic devices.

Nonvolatile Electrical Control and Heterointerface‐Induced Half‐Metallicity of 2D Ferromagnets

“…The ongoing research on emerging 2D ferromagnetic materials mainly follows two directions: (i) the pursuit of high‐performance vdW ferromagnets and (ii) the application of experimentally known vdW ferromagnets . The former aims to pursue new vdW ferromagnetic materials possessing superior properties, such as high‐mobility ferromagnetic semiconductors, half metals with large spin gaps, and robust ferromagnets with high Curie temperature . The latter focuses on the rational control of atom‐thick vdW ferromagnets to accomplish better performance in nanodevices, among which electrical control, via electric field and electrostatic doping, has been verified to be an effective strategy to modulate atomically thin vdW ferromagnets .…”

Large and controllable spin-valley splitting in two-dimensional WS2/h−VN heterostructure

“…[7] On the other hand, h-VN monolayer was predicted to be a ferromagnetic half-metallic material with a high Curie temperature of 768 K, which can be used for spin injection and valley polarization for TMDs monolayer. [28] In the…”

Strain-tunable magnetic anisotropy in two-dimensional Dirac half-metals: nickel trihalides

“…Until now, the halfmetallicity in several pristine 2D systems has been computationally proved. [10][11][12][13] Another distinct class of materials with Dirac states, such as graphene, [14][15][16] silicene, 17,18 monolayer TiB 2 , 19 and hydrogenated arsenene, 20 is characterized by lowenergy fermionic excitations that behave as massless Dirac particles with linear dispersion. By combining the two fascinating properties of half-metallicity and Dirac spectrum, a potentially more interesting state, namely Dirac half-metal (DHM), which is characterized by a band structure with a gap in one channel but a Dirac cone in the other, has been proposed based on a model calculation.…”