The structure and electronic properties of hexagonal Fe2Si

Abstract

On the basis of first principle calculations, we show that a hexagonal structure of Fe2Si is a ferromagnetic crystal. The result of the phonon spectra indicates that it is a stable structure. Such material exhibits a spin-polarized and half-metal-like band structure. From the calculations of generalized gradient approximation, metallic and semiconducting behaviors are observed with a direct and nearly 0 eV band gap in various spin channels. The densities of states in the vicinity of the Fermi level is mainly contributed from the d-electrons of Fe. We calculate the reflection spectrum of Fe2Si, which has minima at 275nm and 3300nm with reflectance of 0.27 and 0.49, respectively. Such results may provide a reference for the search of hexagonal Fe2Si in experiments. With this band characteristic, the material may be applied in the field of novel spintronics devices.

Room-Temperature Ferromagnetism in Two-Dimensional Fe2Si Nanosheet with Enhanced Spin-Polarization Ratio

“…The optimized lattice constants of Fe 2 Si bulk with HSE06 method are a = b = 4.07 and c = 5.11 Å, agreeing well with experimental values . The spin-polarized electronic band structures of Fe 2 Si calculated with PBE method exhibit half-metallic-like property, as shown in Figure S1 (see Supporting Information), which is consistent with previous theoretical study at the same calculation level . Considering the strong-correlated effect, however, the electronic band structure calculated with the screened HSE06 hybrid function indicates that the hexagonal Fe 2 Si is a ferromagnetic metal, as shown in Figure c.…”

“…Experimentally, single phase Fe 2 Si alloy can be obtained by a rapid quenching technique . With novel high-saturation magnetization, low coercivity, high permeability, low magnetostrictive coefficient, low magnetocrystalline anisotropy, and possible half-metallic like band structure, Fe 2 Si has great potential applications in high-power transformers, microwaves, motors, high-frequency applications, and so forth. , …”

MAELAS: MAgneto-ELAStic properties calculation via computational high-throughput approach

“…Sun et al reported MAE values with the screened hybrid Heyd-Scuseria-Ernzerhof (HSE06) functional smaller than with PBE for 2D Fe 2 Si [65,66]. Chi Pui Tang et al calculated some electronic properties for bulk Fe 2 Si finding that the densities of states in the vicinity of the Fermi level is mainly contributed from the d-electrons of Fe [67]. In Table 3, we observe that the overall anisotropic magnetostriction given by MAELAS is rather small, which makes this material interesting for high-flux core applications because it can reduce hysteresis loss [68].…”

Towards rational design of low-dimensional material: from structure prediction to molecular engineering

“…例如, 针对具有磁性的Fe 2 Si体相结构 [58,59] , 通过截取 特定的二维区域, 能够形成六方密堆、具有准单原子 层厚度的特殊二维结构 [57] , 如图3所示. 在该结构中, [67] ; 通过氢化石墨烯表面 可以获得石墨烷 [68] ; 通过硅烯 [69] 表面硅原子、二聚 体、一维原子链修饰, 可以获得具有半导体特性的二 维硅结构 [70] ; 从MoS 2 结构出发, 通过原子替换可以获 [57] (网络版彩图) 属, X=S、Se、Te) [71,72] ; 此外, 基于应力 [73] 与表面化学 修饰 [74] 等方法可以诱导二维过渡金属硫族化合物中 的相变, 如形成独特的三聚体或者链状结构, 如图5所 示 [75,76] .…”