Electron Spin Research Articles

The influence mechanism of phospholipids structure and composition changes caused by oxidation on the formation of flavor substances in sturgeon caviar

The oxidation-induced phospholipids (PLs) underwent structural and compositional analysis, alongside the establishment of a simulation system to verify the link between phospholipid oxidation and flavor substances formation in sturgeon caviar. Structural alterations of PLs were tracked using 31P and 1H nuclear magnetic resonance (NMR), electron spin resonance spectroscopy (ESR), and Raman spectroscopy. The findings revealed a reduction in phosphatidylcholine (PC) and phosphatidylethanolamine (PE) from 82.3% and 10.4% to 58.2% and 5.8% respectively. Free radical signals exhibited an initial increase followed by a decrease. The diminished intensity in Raman spectra at 970 and 1080 cm−1 indicated reduced fat unsaturation attributable to PLs oxidation. Correlation analysis highlighted a significant association between PC and PE containing C22:6, C20:5, C20:4, and C18:2 with flavor substances, suggesting their role as key precursors for flavor development. This study established a theoretical basis for understanding the change of flavor quality in sturgeon caviar during storage.

Facile Exfoliation of Few-Layer Sn-Based Nanosheets for Self-Powered Photo-Electrochemical and All-Optical Modulation Applications.

Few-layer tin (Sn)-based nanosheets (NSs) with a thickness of ≈2.5nm are successfully prepared using a modified liquid phase exfoliation (LPE) method. Here the first exploration of photo-electrochemical (PEC) and nonlinear properties of Sn NSs is presented. The results demonstrate that the PEC properties are tunable under different experimental conditions. Additionally, Sn NSs are shown to exhibit a unique self-powered PEC performance, maintaining a good long-term stability for up to 1 month. Using electron spin resonance, active species, such as hydroxyl radicals (·OH), superoxide radicals (·O2 -), and holes (h+), are detected during operations, providing a deeper understanding of the working mechanism. Furthermore, measurements of nonlinear response reveal that Sn NSs can be effective for all-optical modulation, as it enables the realization of all-optical switching through excitation spatial cross-phase modulation (SXPM). These findings present new research insights and potential applications of Sn NSs in optoelectronics.

Strength, plasticity, and spin transition of Fe-N compounds in planetary cores

Elastic and plastic properties of Fe-light element alloys and compounds are needed to determine the compositions and dynamics of planetary cores. Elastic strength and plastic deformation mechanisms and their relationship to electronic properties of ε-Fe7N3 and γ'-Fe4N mixture were investigated by x-ray diffraction and x-ray emission spectroscopy in the diamond anvil cell from 1 bar up to 60 GPa. X-ray diffraction shows that ε-Fe7N3 reaches a pressure of 15–20 GPa before undergoing bulk plasticity at a differential stress of 4.4–10.4 GPa. ε-Fe7N3 is stronger than γ'-Fe4N and hcp-Fe which achieve a flow stress of 1.5–3.6 GPa at 10–15 GPa and 2–3 GPa at ∼20 GPa, respectively. X-ray emission spectroscopy shows that a decrease in electronic spin moment begins before and completes after plastic flow onset for each nitride, suggesting that pressure-driven changes in electronic arrangement do not trigger a plastic response although they may modify the strength and plastic behavior of Fe-N compounds. Plastic deformation in ε-Fe7N3 and hcp-Fe results in a preferred orientation of (0001) normal to maximum compression, while γ'-Fe4N develops a maximum in the (110). These observations may be combined with measurements of elasticity to model seismic properties of cores of small planetary bodies such as Mars, Mercury, and the Moon.

Antiferromagnetic Chern insulator with large charge gap in heavy transition-metal compounds

Despite the discovery of multiple intrinsic magnetic topological insulators in recent years the observation of Chern insulators is still restricted to very low temperatures due to the negligible charge gaps. Here, we uncover the potential of heavy transition-metal compounds for realizing a collinear antiferromagnetic Chern insulator (AFCI) with a charge gap as large as 300 meV. Our analysis relies on the Kane-Mele-Kondo model with a ferromagnetic Hund coupling JH\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$J_{{\ extrm{H}}}$$\\end{document} between the spins of itinerant electrons and the localized spins of size S. We show that a spin-orbit coupling λSO≳0.03t\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\lambda _{{\ extrm{SO}}} \\gtrsim 0.03t$$\\end{document}, where t is the nearest-neighbor hopping element, is already large enough to stabilize an AFCI provided the alternating sublattice potential δ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\delta$$\\end{document} is in the range δ≈SJH\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\delta \\approx SJ_{{\ extrm{H}}}$$\\end{document}. We establish a remarkable increase in the charge gap upon increasing λSO\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\lambda _{{\ extrm{SO}}}$$\\end{document} in the AFCI phase. Using our results we explain the collinear AFCI recently found in monolayers of CrO and MoO with charge gaps of 1 and 50meV\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$50\\,\\hbox {meV}$$\\end{document}, respectively. In addition, we propose bilayers of heavy transition-metal oxides of perovskite structure as candidates to realize a room-temperature AFCI if grown along the [111] direction and subjected to a perpendicular electric field.

Analogous Chain Selenite Chlorides Ba2M(SeO3)2Cl2 (M = Cu2+, Ni2+, Co2+, Mn2+) and Pb2Cu(SeO3)2Cl2 with Tunable Spin S: Syntheses and Characterizations.

A series of analogous chain selenite chlorides Ba2M(SeO3)2Cl2 (M = Cu 1, Ni 2, Co 3, Mn 4) and Pb2Cu(SeO3)2Cl2 5 with tunable spin S from S = 1/2 to S = 5/2 have been hydrothermally synthesized and characterized. These analogues crystallized in the orthorhombic Pnnm space group (monoclinic P21/n space group for 5) all containing M2+-SeO3-M2+ spin chains, which are further separated by the Ba2+ ions (Pb2+ for 5). The magnetic susceptibility results of 1, 2, and 5 show broad maxima around 80.0, 18.9, and 78.0 K, respectively, indicating good one-dimensional (1D) magnetism. Meanwhile, no long-range order (LRO) is observed down to 2 K for both 1 and 5, while the isostructural compounds 2, 3, and 4 exhibit LRO at 3.4 K, 10.8 K, and 5.7 K, respectively, which are further confirmed by the heat capacity and electron spin resonance results, as well as the observed spin-flop transitions in the M-H curves measured at 2 K below TN. The magnetizations of 1-5 at 7 T are still far from saturation. In addition, thermal stability and FT-IR and UV-vis-NIR spectroscopy of 1-5 are reported.

A dual-functional α-diketone-based disulfide monomer for visible LED photopolymerization: Mitigating volumetric shrinkage and triggering polymerization

A α-diketone-based disulfide monomer (OHS), which serves the function of both volumetric shrinkage decreases and photopolymerization initiation under the irradiation of 405 light-emitting diode (LED) was designed and synthesized. The photochemical and photoinitiating performances were study by ultraviolet–visible spectrophotometer, electron spin resonance spin trapping (ESR-ST) experiments and real-time infrared spectrometer (FTIR). Despite OHS exhibits weak absorption at approximately 405 nm, OHS can effectively produce aromatic sulfur radicals to induce photopolymerization of itself and the bisphenol A glycerolate dimethacrylate (Bis-GMA)/triethylene glycol dimethacrylate (TEGDMA) photopolymerizable system under 405 nm LED exposure. With increasing OHS addition, the final double bond conversion and maximum polymerization rate of the Bis-GMA/TEGDMA system improved, reaching up to 86.0% and 2.33% s-1, respectively. Importantly, OHS significantly reduces the volumetric shrinkage ratio of the Bis-GMA/TEGDMA photopolymerizable system, with the volumetric shrinkage ratio (5.01%) of the system containing 5% OHS declining by almost 50% compared to that (8.51%) of the control system without OHS. This reduction is attributed to reversible characteristic of the disulphide bonds and intermolecular hydrogen bondings. Furthermore, OHS has little influence on the gelation ratio, thermostability, and frictional resistance of the cured film.

Refining metallic nano-copper by electron-rich black carbon for superior Fenton-like catalysis in water purification: The capacitive regulation of corrosive electron transfer

Transition metals are promising catalysts for environmental remediation. However, their low reactivity, poor stability and weak reusability largely limit practical applications. Herein, we report that the electron-rich dissolved black carbon (DBC) incorporated into the nanoscale zero-valent copper (nZVCu) can boost intrinsic reactivity, structural stability and cyclic reusability for superior peroxymonosulfate (PMS) activation and pollutant degradation. A series of refractory pollutants can be effectively removed on the DBC/nZVCu, in comparison with the nZVCu reference. Hydroxyl radical (‧OH) is identified as the dominant reactive oxygen species by electron spin resonance (ESR) and chemical quenching tests, mediated by the metastable Cu(III) as the key reactive intermediate. The electron-rich DBC protects nanoscale Cu from oxidative corrosion to slow down the surface formation of inert CuO layer, rendered by the thermodynamically and dynamically capacitive regulation of corrosive electron transfer from metallic core. By this refining way, the conducive DBC improves the neighboring utilization of reactive electron during metal corrosion, oxidant activation, radical generation and pollutant degradation in Fenton-like catalysis. Our findings suggest that the ubiquitous DBC can be an efficient chelating agent to refine transition metals by serving as the surface deactivator and electron mediator, and take new insights into their environmental and agricultural geochemistry.

Nonadiabatic Tunneling in Chemical Reactions.

Quantum tunneling can have a dramatic effect on chemical reaction rates. In nonadiabatic reactions such as electron transfers or spin crossovers, nuclear tunneling effects can be even stronger than for adiabatic proton transfers. Ring-polymer instanton theory enables molecular simulations of tunneling in full dimensionality and has been shown to be far more reliable than commonly used separable approximations. First-principles instanton calculations predict significant nonadiabatic tunneling of heavy atoms even at room temperature and give excellent agreement with experimental measurements for the intersystem crossing of two nitrenes in cryogenic matrix isolation, the spin-forbidden relaxation of photoexcited thiophosgene in the gas phase, and singlet oxygen deactivation in water at ambient conditions. Finally, an outlook of further theoretical developments is discussed.

A quantum sensor for atomic-scale electric and magnetic fields

The detection of faint magnetic fields from single-electron and nuclear spins at the atomic scale is a long-standing challenge in physics. While current mobile quantum sensors achieve single-electron spin sensitivity, atomic spatial resolution remains elusive for existing techniques. Here we fabricate a single-molecule quantum sensor at the apex of the metallic tip of a scanning tunnelling microscope by attaching Fe atoms and a PTCDA (3,4,9,10-perylenetetracarboxylic-dianhydride) molecule to the tip apex. We address the molecular spin by electron spin resonance and achieve ~100 neV resolution in energy. In a proof-of-principle experiment, we measure the magnetic and electric dipole fields emanating from a single Fe atom and an Ag dimer on an Ag(111) surface with sub-angstrom spatial resolution. Our method enables atomic-scale quantum sensing experiments of electric and magnetic fields on conducting surfaces and may find applications in the sensing of spin-labelled biomolecules and of spin textures in quantum materials.

Engineering Metal Electron Spin Polarization to Regulate p‐Band Center of Se for Enhanced Sodium‐Ion Storage

AbstractSluggish ion diffusion of large sodium ions is one of the main drawbacks challenging the development of metal selenides‐based anode materials for sodium‐ion batteries (SIBs). A spin‐state regulating strategy is first proposed in this work to lift the p‐band center (ɛp) of Se for a fast Na+ transfer kinetic in (Co,Cu)Se2. By utilizing the electron transfer from Cu to Co, the π‐symmetry t2g of Co is fully occupied to decrease the spin polarization. The resultant electron repulsion between Co and Se weakens Co–Se bond to lift the ɛp of Se. The enhanced sodium adsorption energy effectively accelerates the ion transfer at the active material–electrolyte interface. As a result, the (Co,Cu)Se2/NC electrode exhibits an superior sodium storage performance with a capacity of 445 mAh g−1 at 0.2 A g−1, 312 mAh g−1 at 50 A g−1, and 363 mAh g−1 after 10 000 cycles at 10.0 A g−1. The insight into the working mechanism of regulating spin‐state of metals to lift the p‐band center of Se can provide guidelines for the development of both metal selenides‐based anode material and high‐performance SIBs.

Ozone nanobubble technology as a novel AOPs for pollutants degradation under high salinity conditions

Conventional water treatment systems frequently exhibit diminished efficiency at high salinity - a significant issue especially for real industrial effluents - mostly due to the creation of intricate structures between pollutants and salts. One of the primary obstacles associated with high salinity conditions is the generation of by-products that pose additional hurdles for treatment. In this work, we have investigated the novel advanced oxidation process a so-called ozone nanobubble technology for degradation of the pollutants at high salinity conditions. The mass transfer is often the rate-limiting step in gas-liquid process and the poor rate of mass transfer diminishes the overall efficacy. One of the primary disadvantages associated with ozone is its restricted solubility and instability when dissolved in an aqueous solution. These characteristics impose limitations on its potential applications and need the use of specialized systems to facilitate gas-liquid interaction. In this work, we have also suggested enhancing the ozonation process through the utilization of ozone nanobubbles. The findings of our experiment and subsequent analysis indicate that the presence of nanobubbles enhances the process of ozonation through three key mechanisms: (i) an increased mass transfer coefficient, (ii) a higher rate of reactive oxygen species (ROS) generation attributed to the charged interface, and (iii) the nanobubble interface serving as an active surface for chemical reactions. The predicted mass transfer coefficients were found to range from 3 to 3.5 min−1, a value that is notably greater than that seen for microbubbles. The study showcased the degradation of methylene blue dye through the utilization of ozone nanobubbles, which exhibited a much higher rate of dye degradation compared to ozone microbubbles. The confirmation of the radical degradation mechanism was achieved by the utilization of electron spin resonance (ESR) measurements. The developed process has high potential for application in industrial scale textile wastewater treatment.

Photophysical Properties and Photovoltaic Performance of Sensitizers with a Bipyrimidine Acceptor

Molecular engineering is a crucial strategy for improving the photovoltaic performance of dye-sensitized solar cells (DSSCs). Despite the common use of the donor–π bridge–acceptor architecture in designing sensitizers, the underlying structure–performance relationship remains not fully understood. In this study, we synthesized and characterized three sensitizers: MOTP-Pyc, MOS2P-Pyc, and MOTS2P-Pyc, all featuring a bipyrimidine acceptor. Absorption spectra, cyclic voltammetry, and transient photoluminescence spectra reveal a photo-induced electron transfer (PET) process in the excited sensitizers. Electron spin resonance spectroscopy confirmed the presence of charge-separated states. The varying donor and π-bridge structures among the three sensitizers led to differences in their conjugation effect, influencing light absorption abilities and PET processes and ultimately impacting the photovoltaic performance. Among the synthesized sensitizers, MOTP-Pyc demonstrated a DSSC efficiency of 3.04%. Introducing an additional thienothiophene block into the π-bridge improved the DSSC efficiency to 4.47% for MOTS2P-Pyc. Conversely, replacing the phenyl group with a thienothiophene block reduced DSSC efficiency to 2.14% for MOS2P-Pyc. Given the proton-accepting ability of the bipyrimidine module, we treated the dye-sensitized TiO2 photoanodes with hydroiodic acid (HI), significantly broadening the light absorption range. This treatment greatly enhanced the short-circuit current density of DSSCs owing to the enhanced electron-withdrawing ability of the acceptor. Consequently, the HI-treated MOTS2P-Pyc-based DSSCs achieved the highest power conversion efficiency of 7.12%, comparable to that of the N719 dye at 7.09%. This work reveals the positive role of bipyrimidine in the design of organic sensitizers for DSSC applications.

Manipulating Ferroelectric Polarization and Spin Polarization of 2D CuInP2S6 Crystals for Photocatalytic CO2 Reduction.

Manipulating electronic polarizations such as ferroelectric or spin polarizations has recently emerged as an effective strategy for enhancing the efficiency of photocatalytic reactions. This study demonstrates the control of electronic polarizations modulated by ferroelectric and magnetic approaches within a two-dimensional (2D) layered crystal of copper indium thiophosphate (CuInP2S6) to boost the photocatalytic reduction of CO2. We investigate the substantial influence of ferroelectric polarization on the photocatalytic CO2 reduction efficiency, utilizing the ferroelectric-paraelectric phase transition and polarization alignment through electrical poling. Additionally, we explore enhancing the CO2 reduction efficiency by harnessing spin electrons through the synergistic introduction of sulfur vacancies and applying a magnetic field. Several advanced characterization techniques, including piezoresponse force microscopy, ultrafast pump-probe spectroscopy, in situ X-ray absorption spectroscopy, and in situ diffuse reflectance infrared Fourier transformed spectroscopy, are performed to unveil the underlying mechanism of the enhanced photocatalytic CO2 reduction. These findings pave the way for manipulating electronic polarizations regulated through ferroelectric or magnetic modulations in 2D layered materials to advance the efficiency of photocatalytic CO2 reduction.

Imaging Nanomagnetism with Interference and Spins of Electrons

Imaging Nanomagnetism with Interference and Spins of Electrons

Probing spin fractionalization with electron spin resonance based on scanning tunneling microscopy

Probing spin fractionalization with electron spin resonance based on scanning tunneling microscopy

Influence of high-temperature thermal annealing on paramagnetic point defects in silicon-rich silicon nitride films formed in a single-wafer-type low-pressure chemical vapor deposition reactor

The influence of high-temperature thermal annealing on silicon dangling bonds called K centers in Si-rich silicon nitride films grown in a single-wafer-type low-pressure chemical vapor deposition reactor with the SiH2Cl2-NH3 system at 750 °C has been investigated by combining thermal desorption spectroscopy (TDS), Fourier transform infrared spectroscopy-attenuated total reflection, spectroscopic ellipsometry, and electron spin resonance. In the TDS analysis, H2 desorption from the nitride films was detected above about 600 °C. It is found that thermal annealing at 750 and 900 °C caused a slight decrease in the K center density and a change in the g value of K centers, which are considered to be caused by changes in the atomic structure of the nitride films. On the other hand, thermal annealing at 1050 °C resulted in a substantial decrease in the K center density and the generation of paramagnetic defects with unprecedented characteristics. The findings in this study are expected to provide important guidelines for the design of manufacturing processes of nonvolatile memories.

Dwell time and spin polarization for electron in single ferromagnetic-stripe device modulated by spin–orbit couplings

Considering both Zeeman effect and spin–orbit coupling, we calculate dwell time for electron in single ferromagnetic-stripe device (SFSD), which can be constructed by patterning a nanosized ferromagnetic stripe on the surface of GaAs/AlxGa1-xAs heterostructure. Due to an intrinsic symmetry in the SFSD, dwell time is independent of electron spins, if only Zeeman effect is involved. However, the intrinsic symmetry is broken by spin–orbit coupling, which gives rise to spin-dependent dwell time for electron in the SFSD. As a result, electron spins can be separated in time dimension, which induces an obvious electron-spin polarization effect in the SFSD. Spin polarization ratio can be efficaciously modified by interfacial confining electric-field or strain engineering, which attributes to the dependence of effective potential felt by electron in the SFSD on spin–orbit couplings. Thus, the SFSD can act as a controllable temporal electron-spin splitter, a class of electron-spin polarized sources in semiconductor spintronics.

New nano-complexes targeting protein 3S7S in breast cancer and protein 4OO6 in liver cancer investigated in cell line

Cancer, a lethal ailment, possesses a multitude of therapeutic alternatives to combat its presence, metal complexes have emerged as significant classes of medicinal compounds, exhibiting considerable biological efficacy, especially as anticancer agents. The utilization of cis-platin in the treatment of various cancer types, including breast cancer, has served as inspiration to devise novel nanostructured metal complexes for breast cancer therapy. Notably, homo- and hetero-octahedral bimetallic complexes of an innovative multifunctional ether ligand (comprising Mn(II), Ni(II), Cu(II), Zn(II), Hg(II), and Ag(I) ions) have been synthesized. To ascertain their structural characteristics, elemental and spectral analyses, encompassing IR, UV–Vis, 1H-NMR, mass and electron spin resonance (ESR) spectra, magnetic moments, molar conductance, thermal analysis, and electron microscopy, were employed. The molar conductance of these complexes in DMF demonstrated a non-electrolytic nature. Nanostructured forms of the complexes were identified through electron microscopic data. At ambient temperature, the ESR spectra of the solid complexes exhibited anisotropic and isotropic variants, indicative of covalent bonding. The ligand and several of its metal complexes were subjected to cytotoxicity testing against breast cancer protein 3S7S and liver cancer protein 4OO6, with the Ag(I) complex (7) evincing the most potent effect, followed by the Cu(II) with ligand (complex (2)), Cis-platin, the ligand itself, and the Cu(II)/Zn(II) complex (8). Molecular docking data unveiled the inhibitory order of several complexes.

Novel amphipathic photoinitiating systems utilizing ethyl violet for acrylate and thiol-based click photopolymerization under 630 nm and 450 nm LED

We conducted the first-ever investigation on the use of amphipathic triphenylmethane dyes ethyl violet (EV), in combination with iodonium salts (Iod) and sodium tetraphenylborate (STPB), as novel visible light photoinitiating systems (PISs), for initiating oil-based photopolymerization of acrylate and thiol-ene, as well as water-based photopolymerization, under 630 nm and 450 nm light-emitting diodes (LED) irradiation. The polymerization kinetics verified the efficient initiation of the EV/STPB/Iod system under two light sources. Differential scanning calorimetry (DSC) and thermal imaging tests further confirmed the crucial role of light in the polymerization process. The potential photolysis mechanism of these systems containing EV was explored through steady-state photolysis, liquid chromatography-mass spectrometry (LC-MS), and electron spin resonance (ESR). This research not only offers a viable approach for developing PISs used for LED photopolymerization technology but also contributes to the development of water-based photopolymerization.

The surface defect of Fe2Ge (001) induces a synergistic spin effect and regulates the surface magnetism

The defect structure leads to the fracture and recombination of chemical bonds, lattice distortion, electron localization, etc., which has a significant improvement on the physical properties of materials, and give them new functions. The unique structure of Fe2Ge forms the surface structure of Ge end face and Fe end face in the direction of (001), but the surface is easy to form defect structure, and affecting its properties. It is found that the spin direction of Ge atom is opposite to the spin direction of Fe atom in perfect Fe2Ge (001) surface structure. When there is VGe defect, the magnetic moments of the perfect Fe2Ge (001) surface and Fe atoms are enhanced. When there are VFe, VFe-Ge and VGe-Fe defects, the magnetic moments of defects Fe2Ge (001) surface and Fe atoms are weakened. The reason is that the spin state electrons of Fe atoms induce Ge atoms to produce spin electrons, which forms a synergistic spin effect. The Hirshfeld Charge distribution and charge spin of Fe and Ge atoms are affected by the local potential field, Ge atoms are excited with spin direction of Fe atoms with VFe and VFe-Ge, and Ge atoms induce magnetic moments with spin direction of Fe atoms with VGe and VGe-Fe. The effects mechanism is that the five orbitals dzz, dxy, dzy, dzx and dxx-yy of Fe atom are greatly affected by the structure of the defect under the action of crystal field, while the s, px, py and pz orbitals are less affected. In VGe and VFe-Ge defects, the spin splitting of the d orbitals is larger to form a larger magnetic moment. In VFe and VGe-Fe defects, the d orbital spin splitting is smaller, and resulting in a smaller magnetic moment. The s, px, py and pz of Ge atoms are greatly affected, the spin splitting of pz is larger than that of px and py orbitals, and indicating that the spin of Ge atoms mainly comes from pz orbitals.