Moments Of Fe Atoms Research Articles

First-principles calculation for hydrogen-doped hematite

Hexagonal α-Fe2O3 is one of the most common functional material used as magnetic semiconductor, and plays an important part in various applications, such as electronic devices etc. Based on the density functional theory, the lattice parameters, density of states and Bader charge analysis of α-Fe2O3 have been calculated using the first-principles calculation with GGA+U method. As Fe is a transition metal element, the value of U can be more accurate by considering the influence of the strong on-site Coulomb interaction between 3d electrons. First, the crystal equilibrium volume, the magnetic moment of Fe atom, and the band gap value of α-Fe2O3 are synthetically researched and compared with those with different U. Results indicate that the calculation model of α-Fe2O3 are in good agreement with the experimental model when the value of U is 6 eV. These parameters can also be adapted to the following doping calculaton. The α-Fe2O3 unit cell has both tetrahedral and octahedral interstitial sites. The calculation of doping formation energy shows that the α-Fe2O3 system is most stable when the doped hydrogen atom is in the tetrahedral interstitial site. The density of states show that the valence band and conduction band compositions are similar for the bulk and hydrogen-doped α-Fe2O3. That is, the valence bands are dominated mainly by both O 2p and Fe 3d orbitals with the O 2p orbitals playing a leading role, while the conduction band is dominated by Fe 3d orbitals. The band gap of α-Fe2O3 decreases from 2.2 to 1.63 eV after hydrogen doping. Also, a strong hybrid peak occurs near the Fermi level after hydrogen doping, which is chiefly composed of Fe 3d orbital, and the O 2p orbital also has a small contribution. The H 1s orbital is mainly in the lower level below the top valence band. Results of the Bader charge analysis and the density of states calculation for partial correlated atoms suggest that the new hybrid peak is chiefly caused by Fe atom which is closest to the hydrogen atom in the crystal cell. In this process, H atom loses electrons, and the nearest neighbors of H atom, i.e. O and Fe atoms, almost obtain all the electrons H atom loses, so H and O atoms are bonded together strongly, causing the hybrid peak, to expand the width of the top valence band and shift down the bottom of the conduction band, so that the band gap decreases and the electrical conductivity increases. Hydrogen doping is suggested to be an effective method to modify the band.

Electronic structure and magnetic properties of PbMO3 (M = Fe, Co, Ni) magnetic perovskites: An ab initio study

We present the electronic, magnetic and structural properties of the magnetic transition metal oxides PbMO 3 (M = Fe , Co , Ni ) in cubic perovskite structure. The calculations are based on the density functional theory (DFT) within plane-wave pseudopotential method and local spin density approximation (LSDA) of the exchange-correlation functional. On-site Coulomb interaction is also included in calculations (LSDA+ U ). The systems are considered in ferromagnetic (FM) and G-type antiferromagnetic (G-AFM) order. FM structures are energetically more favored than G-AFM and than non-magnetic states for all the systems studied. The spin-polarized electronic band structures show that all the structures have metallic property in FM order without Hubbard-U interaction (U eff = 0). However, the inclusion of on-site Coulomb interaction (U eff = 7 eV ) opens a semiconducting gap for majority spin channel of PbFeO 3 and of PbNiO 3 resulting in a half-metallic character. PbCoO 3 system remains as metallic with LSDA+ U scheme. Bonding features of all structures are largely determined by the hybridizations between O–p and d-states of transition metal atoms. The partial magnetic moment of Fe atom in PbFeO 3 is enhanced by inclusion of Hubbard-U interaction (2.55 μB ⇒ 3.78 μB). Total magnetic moments of half-metallic PbFeO 3 and of PbNiO 3 compounds are very close to integer values.

Structures, energetics and magnetic properties of Au<sub>n</sub>SFe<sub>m</sub> and Au<sub>n</sub>Fe<sub>m</sub> clusters for m = 1-5 and n = 1-5, 12 and 32

Simulations of nanoscale systems are important from the understanding point of view of the physics and chemistry involved in describing observed phenomenon. This paper presents the results of systematic theoretical investigation of the structural and magnetic properties of gold-iron complexes at small size scale. Ab initio calculations are performed for AunFem with and without the presence of a sulfur atom, i.e., the clusters AunSFem, where n, m = 1 - 5. The study also includes Au6SFe and Au12Fe in order to investigate how the fully wrapped Fe atom responds to the Au atoms .The study mainly focuses on the geometrical and magnetic changes with a step by step removal of the sulfur atom as a function of the cluster size. It is found that average Au-Fe bond length is increased with increasing number of atoms in the cluster. An increase of Au-Fe bond length would have increased the magnetic moment of the Fe atom, but due to the hybridization of Au and Fe orbitals, the moment converges to about 3.00 μB. This value is higher than the magnetic moment of Fe atom in bulk gold. An enhanced magnetic moment is found on Fe atom even if it is fully wrapped by the Au12 octahedral cluster. From this study it is found that, the cluster stability is increased on the addition of a single sulfur atom to the AunFem clusters. A special stability is observed in Au4SFe, Au6SFe, Au12SFe and Au4SFe2 clusters as the sulfur atom in these clusters is found to be doubly bonded. Generally, the systematic studies on the small sized clusters show an enhanced magnetic moment on the iron atoms bonded to the gold atoms as compared to the corresponding bare iron clusters. This indicates that, the magnetic moment of iron atoms can be enhanced by a complete coating with gold atoms for practical applications. This complete coating can prevent iron from oxidation and may also prevent coalescence of iron clusters and formation of thromboses. The coupling of iron atoms in this work remains ferromagnetic irrespective of the number of gold atoms in the cluster.Keywords: Cluster, Magnetic moment, Coating, Nanoparticles.

Density functional study of half-metallic property on B2 disordered Co2FeSi

First principle calculations on the magnetic properties and spin polarization of the B2 disordered Co2FeSi full Heusler alloy have been carried out along with that of ordered L21 structure. The linear augmented plane wave method, within the LDA+U approximation, gives the magnetic moment value as predicted by Slater-Pauling rule. A small band gap in the minority band structure around the vicinity of the Fermi level results in half-metallicity or 100 % spin polarization in L21 ordered structure. The calculations also showed that the half-metallicity vanishes at moderate percentages of B2 disorders due to creation of new states around the Fermi level in the minority DOS but at low and high levels of disorder, the half-metallicity was retained. The variation in the magnetic moments of Co2FeSi with change in the % disorder was attributed to the changes in the local magnetic moments of Co, Fe, and Si atoms which vary with change in % disorder.

Strain effects on the structural, magnetic, and thermodynamic properties of the Au(001)/Fe(001) interface from first principles

The structural, magnetic, and thermodynamic properties of the Au(001)/Fe(001) interface are investigated as a function of the in-plane strain using density functional theory calculations for two different Au slab thicknesses: 2 and 8 monolayers. The structural and magnetic properties are analyzed by studying the interlayer distance in the direction perpendicular to the interface and the atomic magnetic moments of Fe atoms, as a function of the in-plane strain. The structural study evidences both the bulk elastic and surface and interface contributions. The atomic magnetic moments of Fe atoms are essentially dependent on their local environment (number and distance of the Fe first neighbors). Thermodynamic properties of the interface are investigated through the calculation of the interface energy and interface stress. These thermodynamic quantities are subsequently used in a simple model to evaluate the strain state of an ideal spherical symmetric Fe@Au core-shell nanoparticle. The surface elastic effects are found to be significant for nanoparticles of diameter smaller than $\ensuremath{\sim}20$ nm and predominant for diameters smaller than $\ensuremath{\sim}2.3$ nm. Interface elastic effects are weaker than surface elastic effects but can not be neglected for very small nanoparticles ($\ensuremath{\lesssim}1.9$ nm) or for thin shells.

Magnetic Properties of Anti-Perovskite Type Transition Metal Ferromagnetic Nitrides

Ferromagnetic anti-perovskite type nitrides (Fig.1) have special features suitable for application to spintronics devices. We have succeeded in growing Co x Fe4 - x N and Co x Mn4 - x N films epitaxially on SrTiO3(001) substrates using molecular beam epitaxy for the first time, and characterized their magnetic properties.1-3 Co3FeN is theoretically predicted to have the large negative spin-polarization of density of states at the Fermi level (P D),4 when Fe atoms are located at the corner (I) sites and Co atoms at the face center (II) sites of the cubic unit cell. We performed x-ray magnetic circular dichroism (XMCD) measurements for the Co3FeN epitaxial films, and evaluated the orbital and spin magnetic moments (m spin) of Co and Fe atoms. Clear XMCD spectra were observed at Fe and Co L 2,3 absorption edges for the Co3FeN films. The m spin per Fe and Co atoms in the Co3FeN film was evaluated to be 2.08 and 1.52 μ B, respectively.3 In the ordered large spin-polarized Co3FeN phase, the m spin per Fe and Co atoms is theoretically predicted to have 3.09 and 1.41 μ B.3 The experimentally obtained m spin of Fe atoms, 2.08 μ B, is close to 2.29 μ B, the site averaged value in Fe4N.5 This result shows that the Fe atoms in the Co3FeN film are located at both I and II sites. Mössbauer measurements were also performed in the Co3FeN film and indicated the consistent results. Growth conditions should be optimized so that Fe and Co atoms are located only at I and II sites, respectively, in order to achieve large spin-polarized Co3FeN. Perpendicular magnetic anisotropy (PMA) was reported in the Mn4N films.6 In addition, large positive P D is predicted by the first principle calculation.7 Co x Mn4 - x N is predicted to have PMA and small saturation magnetization (M S), which is good for application to current-induced magnetic domain wall motion devices. PMA was observed in the Co x Mn4 - x N(x≤0.8) epitaxial films from the magnetization curves measured by a superconductive quantum interface device magnetometer. The M S of the Mn4N and Co0.8Mn3.2N films was 145 and 15 emu/cc at 300 K, respectively. The effective PMA energy of the Mn4N films was about 2.2 Merg/cc.2 The c/a ratio, where c and a are lattice constants along perpendicular and in-plane direction of Mn4N films, respectively, was approximately 0.99.2 We think that PMA in the Mn4N films is induced by the in-plane tensile strain. Distinct XMCD spectra at Mn and Co L 2,3 absorption edges were observed for the Co0.8Mn3.2N film. Shape of the XMCD signal at Mn L 2,3 edges was broader than that of Mn4N. In contrast, XMCD signal at Co L 2,3 edges was sharp. This indicates that the Mn atoms are more likely to locate at II sites, and the Co atoms at I sites instead. It is predicted that the Mn atoms at II sites have the itinerant feature due to band hybridization with neighboring N atoms, while the Co atoms at I sites the localized feature. The element specific magnetization curves measured at the Mn and Co L 3 edges, under the applied magnetic field perpendicular to the films, showed the clear open hysteresis, indicating that PMA surely appeared in the Mn4N and Co0.8Mn3.2N films. 1 T. Sanai, K. Ito, T. Suemasu et al., J. Cryst. Growth 357, 53 (2011). 2 Y. Yasutomi, K. Ito, T. Suemasu et al., J. Appl. Phys. 115, 17A935 (2014). 3 K. Ito, T. Suemasu et al., Appl. Phys. Lett. 103, 232403 (2013). 4 Y. Takahashi et al., J. Magn. Magn. Mater. 323, 2941 (2011). 5 A. Sakuma, J. Magn. Magn. Mater. 102, 127 (1991). 6M. Tsunoda and K. Kabara, presented at ICAUMS2012, 2pPS-47. 7 M. S. Miao et al., Phys. Rev. B 72, 033204 (2005).Fig.1 Lattice structure of anti-perovskite type nitrides.

Site-specific RXMS study on the magnetic electron of magnetite

Magnetite Fe3O4 is the best known magnetic mineral for its attractive properties for various magnetic applications. The magnetic moments of Fe atoms show a collinear ferrimagnetic ordering between tetrahedral A and octahedral B sites in an inverse spinel structure with the chemical formula of [Fe3+]A[Fe2+Fe3+]BO4. The distribution of the Fe2+ and Fe3+ over A and B sites is determined by a delicate balance of the crystal field. The geometrical environment of 3d transition metals strongly affects the distribution and the energy state of magnetic electrons which contributes magnetic moments. The resonant x-ray magnetic scattering (RXMS) allows us to make site-selective structural analysis with respect to the magnetic electron. In order to clarify the behavior of the magnetic electrons in magnetite, we carried out the energy-dependent RXMS near Fe K edge. Depends on the observation related to 3d-4p electric transition to empty bands of unpaired electron, we studied the orbital interaction and the density of state of magnetic electrons in A site and B site of magnetite independently. RXMS intensity measurements were performed by using Rigaku AFC-5u four-circle diffractometers at BL-6C of Photon Factory. Circularly-polarized X-rays were produced by a transmitted-type phase retarder of diamond (111). According to the X-ray magnetic circular dichroism (XMCD) spectrum at the Fe K edge, 48 x-ray energies to perform RXMS measurement were selected. The magnetic form factors for various energies were calculated from the difference in diffraction intensities between left- and right-circular polarized measurements. By examining the energy dependence of the resonant magnetic peaks, the density of state of 3d magnetic electron of Fe were obtained for A and B site through the experimental analysis. In the presentation, the interrelationship between the site geometry and the magnetic electrons in terms of energy state will be discussed.

Selenium adsorption at different coverages on Fe(1 0 0) and Fe(1 1 1): A DFT study

Se adsorption on Fe(1 0 0) and (1 1 1) surfaces is examined using the density functional theory (DFT). Selenium is adsorbed in a distorted bridge on the (1 1 1) surface while in the (1 0 0) surface it prefers a 4-fold hollow site, with energies of −10.36 and −5.25 eV, respectively. Se adsorption results in surface reconstruction. There is some contraction in the case of the (1 0 0) plane for 1/4 and 1/2 ML coverage and some relaxation at 1 ML (4.5%). Contraction increases to 15% for the (1 1 1) plane at ¼ ML. At a higher coverage, there is a non-regular movement of surface metal atoms, and there is almost no change at 1 ML. The magnetic moment for surface Fe atoms decreases with coverage. The most important changes are in the (1 0 0) plane, followed by the (1 1 0) and then the (1 1 1) planes with a reduction of 52%, 24% and 7% respectively. The density of states presents a contribution of Se states at −5.0 and −13.1 eV, when stabilized after adsorption. The Fe–Fe bond weakening is higher in the (1 0 0) plane. Fe–Se bonds are formed at the expense of the metallic bond.

The Influence of Vanadium on Magnetism and Magnetocaloric Properties of Fe 8 0 − x V x B12Si8 (x = 8, 10, and 13.7) Amorphous Alloys

Amorphous soft magnetic Fe80−x VxB12Si8 ribbons (0 ≤ x ≤ 14) have been fabricated by melt spinning technique, and their magnetic and magnetocaloric properties have been studied. The value of magnetocaloric effect has been determined from the measurements of magnetization as a function of temperature and an external magnetic field. The addition of vanadium to the ternary Fe80B12Si8 alloy results in a decrease of the Curie temperature of amorphous alloys, TC, from 473.5 to 335 K. With an increasing V content, the average magnetic moment of Fe atom and the magnetic entropy change also decrease. Fe66.3V13.7B12Si8 alloy exhibits the highest refrigeration capacity of 93.7 J kg−1 and moderate peak magnetic entropy of 1.034 J kg−1 K−1 (TC = 335 K) under the maximum applied field of 2 T. The results from this work showed that V containing amorphous alloy 13.7 at. % is an interesting material and potential candidate for magnetic refrigerants working near room temperature. The observed −ΔSMmax values compare favorably with other amorphous Fe-based alloys.

The molecular and magnetic structure of carbon-enclosed and partially covered Fe55 particles

The structure and magnetic moment distribution are studied for an iron nanoparticle with varying degree of carbon adatom coverage. The limiting models of the study are the clean icosahedral Fe55 particle and the iron particle completely enclosed in carbon cages. Between the two extrema, partially covered particles are considered. The iron cluster with partial coverage of carbon adatoms represents a model of active catalysts in the chemical vapor deposition synthesis of carbon nanotubes. The investigated structures are the bare Fe55 cluster, Fe55N4C(x) (x = 27, 37, 47, 54, 65), and Fe55 encapsulated inside C180 and C240. The two latter are extreme examples of an iron particle completely enclosed in a carbon network. Fe55@C180 and Fe55@C240 present novel structures resembling the endohedral metallofullerenes. Two structural isomers of the Fe55@C180 are considered. Enclosing the Fe55 cluster inside C180 and C240 fullerenes gives rise to changes in the Fe-Fe bond lengths. This alters the magnetic structure of the iron cluster considerably. The interaction between the fullerenes and the enclosed iron cluster is reflected in a charge transfer of 8-13 electrons in the considered endohedral complexes. The localization of atomic charges on the C180 and C240 cages suggests site-selective reactivity of the endohedral complexes. The total magnetic moments of the Fe55N4C(x) nanoparticles vary with the degree of adatom coverage. The magnetic moments of individual Fe atoms depend strongly on the element of the nearest-neighbor atoms and on the coordination number and carry therefore information about the local chemistry.

Estimation of Order Parameter and Spin Moment of Fe<sub>3</sub>Pt by White X-Ray Diffraction Method

Diffraction intensities of a single crystal of Fe3Pt alloy have been measured by using white X-rays of synchrotron radiation. The observed intensities have been compared with the calculated ones for fundamental and superlattice reflections. By normalizing the calculated intensities of fundamental reflections to the observed ones and evaluating the ratio of the observed intensity of superlattice reflection to the calculated ones, we have estimated the order parameter as 0.82±0.03. The obtained order parameter has been applied to an analysis of the X-ray magnetic diffraction data to estimate the spin moment of Fe and Pt atoms in this alloy.

Electronic and magnetic properties of Co2−xFexCrAl alloys: Ab initio calculations

We performed density functional theory (DFT) calculations within the full‐potential linearized augmented plane wave (FLAPW) method to study the electronic and magnetic properties of Co2−xFexCrAl (x = 0, 0.25, 0.5, 0.75, and 1) alloys. The calculations indicate that Co2−xFexCrAl alloys are half‐metallic within the whole studied range. The local magnetic moments of Fe atoms are found to be anti‐ferromagnetically aligned with those of Cr and Co atoms. This causes a decrease of the total magnetic moments of the alloyed structures from 12 to 8 µB/cell as a function of Fe concentration obeying the Slater–Pauling rule.

Electronic structure and magnetism of Ti2FeSi: A first-principles study

Electronic structure and magnetic calculations properties of the Ti-based Heusler alloys Ti2FeSi have been studied using the first-principles projector augmented wave potential within the generalized gradient approximation taking into account the Coulomb interaction. Calculated the density of states are discussed in terms of the contribution of Ti 3d24s2, Fe 3d64s2, and Si 3s23p2 partial density of states and the spin magnetic moments were also calculated. The density of states of the Ti2FeSi compound shows the spin-up electrons are metallic, but the spin-down electrons are semiconductor with a gap of 0.612eV. Si atom shows only a small magnetic moment, but the magnetic moment of Fe atom is antiparallel to that of Ti atoms. The Ti2FeSi Heusler compound has a magnetic moment of 2μB at the equilibrium lattice constant a=6.057Å.

Effect of site disorder on the electronic properties of Fe2VAl Heusler alloy

• The role of site-disorder on physical properties of Fe 2 VAl has been investigated through experiments as well as DFT calculations. • Metal to semiconductor-like behaviour in electrical transport of anti-site disordered Fe 2 VAl was consistently explained. • Both itinerant and localized magnetic behaviours of anti-site disordered Fe 2 VAl are discussed. • Justification of metallic-like transition in site-disordered Fe 2 VAl is given. Ab initio calculations on ordered L2 1 structure of Fe 2 VAl alloy have been carried out by introducing B2, DO 3 , A2′ and XY–XZ type disorders in order to understand the role of anti-site disorder on magnetic and transport properties. These studies show an enhancement of individual spin moments of anti-site Fe atoms in DO 3 , A2′ and XY–XZ type anti-site disorder, making the Fe 2 VAl alloy magnetically active. These calculations also show that hybridization due to covalent distribution of valance states among the atoms is important in Fe 2 VAl, defining its unusual physical properties. From the density of states spectrum obtained near the Fermi level, we have noticed formation of intermediate defect-like states that couple the edges of the pseudo gap on both sides of the Fermi level, driving the material from semi-metallic to metallic type in electrical transport. We also present experimental results on structural, magnetic and electrical properties of Fe 2 VAl Heusler alloy. A comparison of present experimental data with calculations shows an existence of DO 3 type anti-site disorder due to the Al-deficiency in Fe 2 VAl alloy which causes deviations in theoretical results on the magnetic and transport behaviour of pure Fe 2 VAl. The temperature dependence of electrical transport and magnetic data analysed on the basis of impurity band model which provides convincing evidence for itinerant character of this alloy system with an anti-site disorder.

Correlation of electronic structure and magnetic moment in Fe16N2: First-principles calculations

The structural and magnetic properties of Fe 16 N 2 have been investigated with the help of the GGA+U method. Calculations of the magnetic properties of Fe 16 N 2 indicate that the average magnetic moment of Fe atoms increases in line with the electron correlation effects in Fe 16 N 2 . The differences of magnetic moments for non-equivalent Fe atoms in Fe 16 N 2 mainly result from interstitial N atoms, different degrees of hybridization between non-equivalent Fe atoms and N atoms, and interaction among different d electron orbits of non-equivalent Fe atoms.

The effect of arsenic vacancies on the electronic and magnetic properties of LaFeAs1−xO

By means of the first principles calculations, the influence of arsenic deficiency on the electronic and magnetic properties of the layered phase LaFeAsO was examined. We found that As vacancies affect mainly the near-Fermi Fe-derived bands leading to their splitting and changing their dispersion and the level of filling. The Fermi surface for LaFeAs1−xO adopts a complicated multi-sheet morphology, with a number of linked 2D-like sheets and a set of new sheets (which are absent for ideal LaFeAsO) at the lateral sides of the Brillouin zone. Besides, for the most stable As-deficient phase an antiferromagnetic stripe-like spin configuration was found, for which an inhomogeneous distribution of magnetic moments of Fe atoms arises near and away from vacancy owing to differences in local magnetic moments of non-equivalent Fe atoms.

Bonding character and formation energy of point defects of he and vacancy on (001) surface of bcc iron by first principle calculations

The structure and energy of He impurities and vacancy on (001) surface of bcc iron are investigated by an ab initio method. Three cases for stabilities of a He atom at the surface are found: some of He atoms at surface atomic layers (SAL) relax into vacuum gap; some of surface He atoms at octahedral interstitial site relax into more stable tetrahedral interstitial site; some of surface He atoms still stay at tetrahedral interstitial site. The un-stability of the He atom at the surface system can be explained by deformation mechanism of charge densities and electronic densities of states. It is found that formation energy of the point defects from the topmost SAL to bulk-like atomic layer increase gradually, for example, the formation energies of a monovacancy at the first five topmost SALs are equal to 0.33, 1.56, 2.04, 2.02 and 2.11 eV, respectively. The magnetic moments of Fe atoms in the surface atomic layers are also calculated.

X-Ray Magnetic Diffraction Experiment of Fe<sub>3</sub>Pt Alloy in Order Phase

We have performed X-ray magnetic diffraction experiments of a ferromagnetic binary alloy Fe3Pt in order phase, and have measured separately spin and orbital magnetic form factors. By a curve-fitting analysis in which atomic-model form factors of Fe-3d and Pt-5d electrons under the dipole approximation are assumed, we have obtained the spin and orbital magnetic moments of Fe and Pt atoms separately. The present result is comparable to those of other experimental and theoretical studies, which shows the validity of this experimental method.

Atomic, electronic and magnetic properties of Fe80P11C9 amorphous alloy: A first-principles study

First principles molecular dynamics was used to investigate the atomic, electronic and magnetic properties of Fe80P11C9 amorphous alloy. Spin effect was found to influence the local structure at room temperature by increasing the FeFe bond length as well as lowering the intensity. The magnetization mostly comes from Fe 3d states, accompanying with a small contribution from P 3p as well as C 2p states. Fe, P, and C exhibited an average magnetic moment of 2.055μB, −0.070μB and −0.124μB respectively. The magnetic moment of Fe atom is greatly affected by its corresponding Voronoi polyhedra, less metalloid element of P, C and more Fe in the cluster lead to a larger magnetization of the centered Fe atom. Therefore, it was proposed to improve the magnetization by adjusting the components of dominant clusters. The bond strength of FeP and FeC are closely related with the bond length and FeC bond is more covalent than FeP bond.

The structural, electronic and magnetic properties of iron nanowires with different diameters

The electronic structure of iron nanowires with transverse dimensions up to 9 Å was calculated using the density functional theory methods. The calculations were carried out taking into account not only the transverse but also the longitudinal optimization of the structural parameters of nanowires. It was shown that the magnetic moments of Fe atoms, on average, decrease with increasing the transverse dimensions of the nanowires and increase with the distance from the nanowire axis. Giant magnetic anisotropy energy was obtained for Fe1 and Fe9 structures.