Effect Of Fe Atoms Research Articles

Correlation-enhanced spin–orbit coupling in a quantum anomalous Hall insulator Fe2Br2 monolayer with a large band gap and robust ferromagnetism

The large gap is due to correlation-enhanced spin-orbit coupling (SOC) effect of Fe atoms, which equates with artificially increasing the strength of SOC without electronic correlation.

Iron Intercalation in Covalent–Organic Frameworks: A Promising Approach for Semiconductors

Covalent–organic frameworks (COFs) are intriguing platforms for designing functional molecular materials. Here, we present a computational study based on van der Waals dispersion-corrected hybrid density functional theory (UB3LYP-D2, i.e., DFT-D) to design boroxine-linked and triazine-linked COFs intercalated with Fe. Keeping the original P–6m2 symmetry of the pristine COF (COF-Fe-0), we have computationally designed seven new COFs by intercalating Fe atoms between two organic layers. The equilibrium structures and electronic properties of both the pristine and Fe-intercalated COF materials are investigated here. We predict that the electronic properties of COFs can be fine-tuned by adding Fe atoms between two organic layers in their structures. Our calculations show that these new intercalated-COFs are promising semiconductors. The effect of Fe atoms on the electronic band structures and density of states (DOSs) has also been investigated using the aforementioned DFT-D method. The contribution of the d-s...

NiFe-LDHs催化氧气析出反应的密度泛函理论研究

本文采用第一性原理密度泛函理论研究了NiFe层状双氢氧化物析氧反应的机理，针对NiFe-LDHs (100)晶面暴露出来的不同金属作为催化反应的位点，计算了各基元反应的吉布斯自由能，推算出不同金属作为位点的过电位。Fe作为OER的催化位点过电位是0.703 eV，Ni作为OER的催化位点过电位是0.985 eV，通过比较过电位大小，发现0.703 eV更低一些，催化反应更容易实现。并且根据态密度图可以分析出Fe的电子传输能力更强。Fe原子作为OER催化位点的活性比Ni原子好。 In the work, First principles periodic Density functional theory (DFT) calculations were used to investigate the electrochemical oxygen evolution reaction (OER) on NiFe layered double hydrox-ide, NiFe-LDHs (100) surface were exposed different metals, Fe and Ni as the sites of catalytic re-action respectively. The Gibbs free energy of each elementary reaction was calculated and the overpotential of different metals was deduced. When Fe atoms as the OER catalytic sites, the overpotential is 0.703 eV, when Ni atoms as OER catalytic sites, the overpotential is 0.985 eV. By comparing the value of overpotential, catalytic reaction is easier to achieve when the overpoten-tial is 0.703 eV. According to the density of state, it can be concluded that the electron conductivity of Fe is stronger, so the effect of Fe atoms as the OER catalytic activity site is better than Ni atoms.

The effect of Fe atoms on the adsorption of a W atom on W(100) surface

We report a first-principles calculation that models the effect of iron (Fe) atoms on the adsorption of a tungsten (W) atom on W(100) surfaces. The adsorption of a W atom on a clean W(100) surface is compared to that of a W atom on a W(100) surface covered with a monolayer of Fe atoms. The total energy of the system is computed as the function of the height of the W adatom. Our result shows that the W atom first adsorbs on top of the Fe monolayer. Then, the W atom can replace one of the Fe atoms through a path with an energy barrier of 0.99 eV and reduce its energy further. This intermediate site makes the adsorption (and desorption) of W atoms a two-step process in the presence of Fe atoms and lowers the overall adsorption energy by nearly 2.4 eV. This effect results in a more efficient adsorption and desorption of W atoms in the presence of Fe atoms. Our result provides a fundamental mechanism that can explain the activated sintering of tungsten by Fe atoms.