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2017-07-20 | Abundances in Galactic Bulge planetary nebulae from optical, ultraviolet and infrared observations | Iron suffers from high levels of depletion in the highly ionized environments
of planetary nebulae, making the direct determination of undepleted elemental
iron abundances difficult. Zinc, which does not suffer from the same depletion
effects as iron, may be used as a surrogate element to measure iron abundances
as the... | 1707.06672v1 |
2018-05-09 | Graphene-Supported Silver-Iron Carbon Nitride Derived from Thermal Decomposition of Silver Hexacyanoferrate as Effective Electrocatalyst for the Oxygen Reduction Reaction in Alkaline Media | Silver-iron carbon nitride has been obtained by pyrolysis (under inert
atmosphere) of silver hexacyanoferrate(II), precipitated on graphene
nanoplatelets, and examined as electrocatalyst for oxygen reduction reaction in
alkaline media in comparison to silver nanoparticles and iron carbon nitride
(prepared separately in... | 1805.03439v1 |
2018-12-13 | Seeding the Formation of Mercurys: An Iron-sensitive Bouncing Barrier in Disk Magnetic Fields | The inner part of protoplanetary disks can be threaded by strong magnetic
fields. In laboratory levitation experiments, we study how magnetic fields up
to 7 mT influence the aggregation of dust by observing the self-consistent
collisional evolution of particle ensembles. As dust samples we use mixtures of
iron and quar... | 1812.05338v1 |
2019-06-19 | The Modulating Optical Depth of Photoelectric Absorption Edge with Pulse Phase in Accretion-Powered X-ray Pulsars | We report the first discovery of pulse phase modulating optical depths at the
iron K-edge in accretion-powered X-ray pulsars, from Suzaku observations. A
significant modulating optical depth of the iron K-edge is detected for Vela
X-1 and GX 1+4. Similar trends are seen in GX 301-2 and OAO 1657-415, though
with poor st... | 1906.08037v2 |
2019-08-19 | Reverse chemistry of iron in the deep Earth | In this work, we demonstrate a remarkable change of chemical trend of Iron
under high pressure that is of great importance for understanding the
distribution of elements in the Earth's mantle and core. Using first principles
crystal structure search method, we conduct a systematic study of the
propensity of p block ele... | 1908.06569v1 |
2019-12-16 | Iron telluride ladder compounds: Predicting the structural and magnetic properties of BaFe$_2$Te$_3$ | Since the discovery of pressure-induced superconductivity in the two-leg
ladder system BaFe$_2X_3$ ($X$=S, Se), with the 3$d$ iron electronic density $n
= 6$, the quasi-one-dimensional iron-based ladders have attracted considerable
attention. Here, we use Density Functional Theory (DFT) to predict that the
novel $n = 6... | 1912.07749v1 |
2020-02-25 | Heavily Hydride-ion-doped 1111-type Iron-based Superconductors: Synthesis, Physical Properties and Electronic Structure | Iron-based superconductors have grown to be a new continent of high Tc
superconductors comparable to cuprates. The optimal critical temperature (Tc)
of 56 K in electron-doped 1111-type iron oxypnictides attracts considerable
attention of physicists and chemists. Carrier doping is not only essential to
induce supercondu... | 2002.11218v1 |
2020-02-22 | Hemolithin: a Meteoritic Protein containing Iron and Lithium | This paper characterizes the first protein to be discovered in a meteorite.
Amino acid polymers previously observed in Acfer 086 and Allende meteorites
[1,2] have been further characterized in Acfer 086 via high precision MALDI
mass spectrometry to reveal a principal unified structure of molecular weight
2320 Daltons t... | 2002.11688v1 |
2020-07-01 | Orbital selectivity in electron correlations and superconducting pairing of iron-based superconductors | Electron correlations play a central role in iron-based superconductors. In
these systems, multiple Fe $3d$-orbitals are active in the low-energy physics,
and they are not all degenerate. For these reasons, the role of
orbital-selective correlations has been an active topic in the study of the
iron-based systems. In th... | 2007.00181v1 |
2021-06-24 | Polymers' surface interactions with molten iron: a theoretical study | Environmental concerns are the chief drive for more innovative recycling
techniques for end-of-life polymeric products. One attractive option is taking
advantage of C and H content of polymeric waste in steelmaking industry. In
this work, we examined the interaction of two high production polymers, i.e.,
polyurethane a... | 2106.12722v1 |
2021-10-28 | Influence of spin fluctuations on structural phase transitions of iron | The effect of spin fluctuations on the $\alpha$ (bcc) - $\gamma$ (fcc) -
$\delta$ (bcc) structural phase transitions in iron is investigated with a
tight-binding (TB) model. The orthogonal $d$-valent TB model is combined with
thermodynamic integration, spin-space averaging and Hamiltonian Monte Carlo to
compute the tem... | 2110.15003v2 |
2022-02-22 | Many body study of iron(III) bound human serum transferrin | Transferrins are proteins responsible for transporting metal ions in all
vertebrates. However, the iron binding properties of transferrins remain poorly
understood. Iron, as a transition metal, forms ions with partially-occupied 3d
subshells. The electrons within the 3d orbitals of iron-bound transferrin are
therefore ... | 2202.10818v1 |
2022-04-05 | IRON: Inverse Rendering by Optimizing Neural SDFs and Materials from Photometric Images | We propose a neural inverse rendering pipeline called IRON that operates on
photometric images and outputs high-quality 3D content in the format of
triangle meshes and material textures readily deployable in existing graphics
pipelines. Our method adopts neural representations for geometry as signed
distance fields (SD... | 2204.02232v1 |
2022-07-18 | Study of Thin Iron Films for Polarization Analysis of Ultracold Neutrons | The TUCAN (TRIUMF Ultra-Cold Advanced Neutron) collaboration aims to search
for the neutron electric dipole moment (nEDM) with unprecedented precision. One
of the essential elements for the nEDM measurement is a polarization analyzer
of ultracold neutrons (UCNs), whose main component is a magnetized thin iron
film. Sev... | 2207.08441v1 |
2022-09-17 | Theoretical predictions of melting behaviors of hcp iron up to 4000 GPa | The high-pressure melting diagram of iron is a vital ingredient for the
geodynamic modeling of planetary interiors. Nonetheless, available data for
molten iron show an alarming discrepancy. Herein, we propose an efficient
one-phase approach to capture the solid-liquid transition of iron under extreme
conditions. Our ba... | 2209.08220v1 |
2022-10-24 | Electronic properties and surface states of RbNi$_2$Se$_2$ | Iron-based superconductors, with the ThCr$_{2}$Si$_{2}$-type tetragonal
structure (122 family), due to the iron arsenide/selenide layers exhibit
several characteristic electronic properties. For example, multiband character
mosty associated with the $d$-orbitals of iron and the quasi-two-dimensional
(2D) cylindrical Fe... | 2210.13280v2 |
2023-06-08 | Iron Oxide Nanoparticles as a Contrast Agent for Synchrotron Imaging of Sperm | Fast phase-contrast imaging offered by modern synchrotron facilities opens
the possibility of imaging dynamic processes of biological material such as
cells. Cells are mainly composed of carbon and hydrogen, which have low X-ray
attenuation, making cell studies with X-ray tomography challenging. At specific
low energie... | 2309.03908v1 |
2023-12-05 | Iron and gold thin films: first-principles study | Using density functional theory, we carried out systematic calculations for a
series of ultrathin iron layers with thicknesses ranging from one atomic
monolayer to eleven monolayers (up to about 1.5 nm). We considered three cases:
(1) iron layers both on a gold substrate and coated with gold, (2) iron layers
on a gold ... | 2312.02701v1 |
2024-01-11 | Boundary-induced phase in epitaxial iron layers | We report the discovery of a boundary-induced body-centered tetragonal (bct)
iron phase in thin films deposited on MgAl$_{2}$O$_{4}$ ($001$) substrates. We
present evidence for this phase using detailed x-ray analysis and ab-initio
density functional theory calculations. A lower magnetic moment and a rotation
of the ea... | 2401.05990v1 |
2024-02-05 | Influence of graphene on the electronic and magnetic properties of an iron(III) porphyrin chloride complex | Although iron-based catalysts are regarded as a promising alternative to
precious metal catalysts, their precise electronic structures during catalysis
still pose challenges for computational descriptions. A particularly urgent
question is the influence of the environment on the electronic structure, and
how to describ... | 2402.03544v1 |
1998-05-14 | An RXTE Observation of the Seyfert 1 Galaxy MCG-6-30-15 : X-ray Reflection and the Iron Abundance | We report on a 50 ks observation of the bright Seyfert 1 galaxy MCG--6-30-15
with the Rossi X-ray Timing Explorer. The data clearly show the broad
fluorescent iron line (equivalent width ~ 250 eV), and the Compton reflection
continuum at higher energies. A comparison of the iron line and the reflection
continuum has en... | 9805198v1 |
2002-03-12 | Ionized iron Kαlines in AGN X-ray spectra | The Equivalent Widths (EW) of the He- and H-like iron lines produced in
photoionized, circumnuclear matter of AGN are calculated with respect to both
the reflected and the total continua. We found that the EWs with respect tothe
total continuum may be as large as a few tens of eV, making them observable in
bright Seyfe... | 0203178v1 |
2004-09-14 | Spectroscopic Equilibrium of Iron in Metal-Rich Dwarfs | We analyze twenty five nearby metal-rich G and late-F dwarfs in order to
verify whether the spectroscopic equilibrium (LTE) of iron lines satisfy the
observational constraints imposed by the Infrared Flux Method (angular
diameters) and Hipparcos parallaxes. The atmospheric parameters derived from
iron lines (assuming L... | 0409347v1 |
2004-12-16 | On the thermal behaviour of small iron grains | The optical properties of small spherical iron grains are derived using a
Kramers-Kronig-consistent model of the dielectric function including its
dependence on temperature and size. Especially discussed is the effect of the
size dependence, which results from the limitation of the free path of the free
electrons in th... | 0412425v2 |
2006-11-30 | Instability strips of main sequence B stars: a parametric study of iron enhancement | The discovery of beta Cephei stars in low metallicity environments, as well
as the difficulty to theoretically explain the excitation of the pulsation
modes observed in some beta Cephei and SPB stars, suggest that the iron opacity
``bump'' provided by standard models could be underestimated. We investigate,
by means of... | 0611944v1 |
1998-06-02 | The stabilizing role of itinerant ferromagnetism in inter-granular cohesion in iron | We present a simple, general energy functional for ferromagnetic materials
based upon a local spin density extension to the Stoner theory of itinerant
ferromagnetism. The functional reproduces well available ab initio results and
experimental interfacial energies for grain boundaries in iron. The model shows
that inter... | 9806034v1 |
2001-10-15 | Superconductivity in compressed iron: Role of spin fluctuations | The recent discovery of superconductivity in hexagonal iron under pressure
poses a question about whether it is of conventional (phonon) or unconventional
(magnetic?) origin. We present first-principles calculations of the
electron-phonon coupling in iron at $P\agt 15$ GPa, and argue that a
conventional mechanism can e... | 0110297v1 |
2004-04-15 | High-field magnetoresistance of Fe/GaAs/Fe tunnel junctions | We investigate transport through 6 to 10 nm thin epitaxial GaAs(001) barriers
sandwiched between polycrystalline iron films. Apart from a pronounced
tunneling magnetoresistance effect (TMR) at low magnetic fields we observe a
distinct negative magnetoresistance (MR) at low and a positive MR at higher
temperatures. We s... | 0404351v1 |
2004-06-16 | Development of an interatomic potential for phosphorus impurities in iron | We present the derivation of an interatomic potential for the iron phosphorus
system based primarily on {\it ab initio} data. Transferrability in this system
is extremely problematic, and the potential is intended specifically to address
the problem of radiation damage and point defects in iron containing low
concentra... | 0406356v1 |
2006-12-30 | Low relaxation rate in a low-Z alloy of iron | The longest relaxation time and sharpest frequency content in ferromagnetic
precession is determined by the intrinsic (Gilbert) relaxation rate \emph{$G$}.
For many years, pure iron (Fe) has had the lowest known value of $G=\textrm{57
Mhz}$ for all pure ferromagnetic metals or binary alloys. We show that an
epitaxial i... | 0701004v1 |
1998-01-21 | Total and Parity-Projected Level Densities of Iron-Region Nuclei by the Shell Model Monte Carlo Method | Total and parity-projected level densities of iron-region nuclei are
calculated microscopically by using Monte Carlo methods for the nuclear shell
model in the complete $(pf+0g_{9/2})$-shell. The calculated total level density
is found to be in good agreement with the experimental level density. The Monte
Carlo calcula... | 9801042v1 |
2001-08-01 | Hybrid Rings of Fixed 8T Superconducting Magnets and Iron Magnets Rapidly Cycling between -2T and +2T for a Muon Collider | Two 2200m radius hybrid rings of fixed superconducting magnets and iron
magnets ramping at 200 Hz and 330 Hz are used to accelerate muons. Muons are
given 25 GeV of RF energy per orbit. Acceleration is from 250 GeV/c to 2400
GeV/c and requires a total of 86 orbits in both rings; 82% of the muons
survive. The total powe... | 0108001v1 |
2008-01-06 | A comparison of the magnetic properties of Proton- and Iron-implanted graphite | In this work we have investigated the changes of the magnetic properties of
highly oriented pyrolytic graphite samples after irradiation either with $\sim
3 \times 10^{14}$ protons or $ 3.5 \times 10^{13} ... 3.5 \times 10^{14}$ iron
ions with energies in the MeV range. Our results show that iron and proton
irradiation... | 0801.0850v1 |
2008-05-22 | Iron nanoparticle formation in a metal-organic matrix: from ripening to gluttony | A simple method for the fabrication of metal nanoparticles is introduced.
Heating metal-organic crystals in vacuum results in the formation of well
defined metal particles embedded in a carbon matrix. The method is demonstrated
for iron-phthalocyanine. At 500C homogeneously distributed iron nanoparticles
with a reasona... | 0805.3416v1 |
2008-08-14 | Synthesis and superconducting properties of the iron oxyarsenide TbFeAsO0.85 | The iron oxyarsenide TbFeAsO0.85 was synthesized by a high-pressure method. A
high-quality polycrystalline sample was obtained and characterized by
measurements of magnetic susceptibility and electrical resistivity. Bulk
superconductivity with Tc of 42 K was clearly established without an F doping
usually conducted to ... | 0808.1948v1 |
2008-11-11 | Theory of Andreev reflection in junctions with iron-based High-$T_c$ superconductors | We construct a theory for low-energy quantum transport in
normal$\mid$superconductor junctions involving the recently discovered
iron-based high-$T_c$ superconductors. We properly take into account both
Andreev bound surface states and the complex Fermi surface topology in our
approach, and investigate the signatures o... | 0811.1775v1 |
2008-11-17 | Effect of hybridization on structural and magnetic properties of iron-based superconductors | We show that the strong hybridization between the iron 3d and the arsenic 4p
orbitals, in the newly discovered iron-based high-T$_{c}$ superconductors,
leads to an explanation of certain experimental observations that are presently
not well understood. The existence of a lattice distortion, the smallness of
the Fe magn... | 0811.2716v1 |
2008-12-17 | Phase-Sensitive measurements on the corner junction of iron-based superconductor BaFe1.8Co0.2As2 | We have made a phase-sensitive measurement on the corner junction of the
iron-based superconductor BaFe1.8Co0.2As2, and observed the typical
Fraunhofer-like diffraction pattern. The result suggests that there is no phase
shift between the a-c face and b-c face of a crystal, which indicates that the
superconducting wave... | 0812.3295v1 |
2009-02-19 | Is the nature of magnetic order in copper-oxides and in iron-pnictides different? | We use the results of first-principles electronic structure calculations and
a strong coupling perturbation approach, together with general theoretical
arguments, to illustrate the differences in super-exchange interactions between
the copper-oxides and iron-pnictides. We show that the two magnetic ground
states can be... | 0902.3450v1 |
2009-03-06 | On the mechanism of high-temperature superconductivity in the iron based pnictides | The recent discovery of superconductivity at moderately high temperature (26
K to 55 K) in doped iron-based pnictides (LnO_{1-x}F_xFeAs, where Ln = La, Ce,
Sm, Pr, Nd, etc.), having layered-structure-like cuprates, has triggered
renewed challenge towards understanding the pairing mechanism.
After reviewing the curren... | 0903.1181v1 |
2009-03-25 | Exchange Constants and Neutron Spectra of Iron Pnictide Materials | We show that the neutron scattering spectra observed in CaFe$_2$As$_2$ by
Zhao et al (arXiv:0903.2686v1) and the highly unusual spatially anisotropic
exchange constants in the iron pnictides derived by Han et al (Phys. Rev. Lett.
102, 107003 (2009)), using electronic structure calculations, can be explained
by assuming... | 0903.4408v1 |
2009-06-11 | To What Extent Iron-Pnictide New Superconductors Have Been Clarified: A Progress Report | In this review, the authors present a summary of experimental reports on
newly discovered iron-based superconductors as they were known at the end of
2008. At the same time, this paper is intended to be useful for experimenters
to know the current status of these superconductors. The authors introduce
experimental resu... | 0906.2045v1 |
2009-09-08 | Is Fermi-surface nesting the origin of superconductivity in iron pnictides?: A fluctuation-exchange-approximation study | We study whether Fermi-surface (FS) nesting can give rise to high-temperature
superconductivity in iron pnictides. Starting with ab initio construction of an
effective four-orbital model, we employ the fluctuation-exchange approximation
to show that FS does not necessarily favor the stripe antiferromagnetic order
obser... | 0909.1413v1 |
2009-10-14 | Magnetic Excitations of Undoped Iron Oxypnictides | We study the magnetic excitations of undoped iron oxypnictides using a
three-dimensional Heisenberg model with single-ion anisotropy. Analytic forms
of the spin wave dispersion, velocities, and structure factor are given. Aside
from quantitative comparisons which can be made to inelastic neutron scattering
experiments,... | 0910.2528v1 |
2010-04-17 | Looking at the superconducting gap of iron pnictides | THz and infrared spectroscopy is widely utilized to investigate the
electrodynamic properties of the novel iron-based superconductors in the normal
and superconducting states. Besides electronic excitations and correlations,
electron-phonon coupling and the influence of magnetism, the experiments yield
important inform... | 1004.2962v1 |
2010-04-27 | Magnetic Ordering in Blocking Layer and Highly Anisotropic Electronic Structure of High-Tc Iron-based Superconductor Sr2VFeAsO3: LDA+U Studies | We calculate electronic structures of a high-Tc iron-based superconductor
Sr2VFeAsO3 by LDA+U method. We assume a checker-board antiferromagnetic order
on blocking layers including vanadium and strong correlation in d-orbits of
vanadium through the Hubbard U. While the standard LDA brings about metallic
blocking layers... | 1004.4741v1 |
2010-06-11 | First Homologous Series of Iron Pnictide Oxide Superconductors (Fe2As2)(Can+1(Sc,Ti)nOy) [n = 3,4,5] with Extremely Thick Blocking Layers | We have discovered first homologous series of iron pnictide oxide
superconductors (Fe2As2)(Can+1(Sc,Ti)nOy) [n = 3,4,5]. These compounds have
extremely thick blocking layers up to quintuple perovskite oxide layers
sandwiched by the Fe2As2 layers. These samples exhibited bulk superconductivity
with relatively high Tc up... | 1006.2355v2 |
2010-08-09 | Electronic structure and total energy of interstitial hydrogen in iron: Tight binding models | An application of the tight binding approximation is presented for the
description of electronic structure and interatomic force in magnetic iron,
both pure and containing hydrogen impurities. We assess the simple canonical
d-band description in comparison to a non orthogonal model including s and d
bands. The transfer... | 1008.1499v4 |
2010-08-25 | Electronic correlations at the alpha-gamma structural phase transition in paramagnetic iron | We compute the equilibrium crystal structure and phase stability of iron at
the alpha(bcc)-gamma(fcc) phase transition as a function of temperature, by
employing a combination of ab initio methods for calculating electronic band
structures and dynamical mean-field theory. The magnetic correlation energy is
found to be ... | 1008.4342v2 |
2010-10-20 | Templated self-assembly of iron oxide nanoparticles | We report on self-assembled iron oxide nanoparticle films on silicon
substrates. In addition to homogeneously assembled layers, we fabricated
patterned trenches of 40-1000 nm width using electron beam lithography for the
investigation of assisted self-assembly. The nanoparticles with a diameter of
20 nm +/- 7% were syn... | 1010.4166v1 |
2011-04-08 | Spin fluctuations in LiFeAs observed by neutron scattering | We report neutron inelastic scattering measurements on the stoichiometric
iron-based superconductor LiFeAs. We find evidence for (i) magnetic scattering
consistent with strong antiferromagnetic fluctuations, and (ii) an increase in
intensity in the superconducting state at low energies, similar to the resonant
magnetic... | 1104.1609v1 |
2011-06-02 | Cubic to hexagonal iron phase transition promoted by interstitial hydrogen | Using ab-initio density functional theory we study the role of interstitial
hydrogen on the energetics of the phase transformation of iron from bcc to hcp
along Bain's pathway. The impurity creates an internal stress field that can be
released through a tetragonal distortion of the lattice, promoting the bcc
(ferromagn... | 1106.0386v1 |
2011-09-19 | Local Quantum Criticality of an Iron-Pnictide Tetrahedron | Motivated by the close correlation between transition temperature ($T_c$) and
the tetrahedral bond angle of the As-Fe-As layer observed in the iron-based
superconductors, we study the interplay between spin and orbital physics of an
isolated iron-arsenide tetrahedron embedded in a metallic environment. Whereas
the spin... | 1109.4131v2 |
2011-11-02 | Thin Film Growth and Device Fabrication of Iron-Based Superconductors | Iron-based superconductors have received much attention as a new family of
high-temperature superconductors owing to their unique properties and distinct
differences from cuprates and conventional superconductors. This paper reviews
progress in thin film research on iron-based superconductors since their
discovery for ... | 1111.0358v1 |
2011-11-15 | The Pressure Effects on Electronic Structure of Iron Chalcogenide Superconductors FeSe$_{1-x}$Te$_x$ | We study the electronic structure of iron-based superconductors
FeSe$_{1-x}$Te$_x$ within the density functional theory. We pay particular
attention to the pressure effects on the Fermi surface (FS) topology, which
seem to be correlated with a critical superconducting temperature TC of iron
chalcogenides and pnictides.... | 1111.3523v2 |
2012-05-15 | Magnetic softness in iron-based superconductors | We examine the relevance of several major material-dependent parameters to
the magnetic softness in iron-base superconductors by first-principles
electronic structure analysis of their parent compounds. The results are
explained in the spin-fermion model where localized spins and orbitally
degenerate itinerant electron... | 1205.3509v1 |
2012-10-10 | Raman scattering in iron-based superconductors | Iron-based superconducting layered compounds have the second highest
transition temperature after cuprate superconductors. Their discovery is a
milestone in the history of high-temperature superconductivity and will have
profound implications for high-temperature superconducting mechanism as well as
industrial applicat... | 1210.2889v1 |
2013-03-25 | TAO pairing: a fully gapped pairing scenario for the Iron-Based Superconductors | Motivated by the fully gapped superconductivity in iron-based superconductors
with uncompensated electron pockets, we propose a spin singlet, but orbital
triplet analogue of the superfluid phase of He-3B. We show that orbital
triplets with a nominal d-wave symmetry at the iron sites can transform as
s-wave pairs under ... | 1303.6325v4 |
2013-11-16 | Coexisting Itinerant and Localized Electrons in Iron-Based Superconductors | The surprising discovery of high-$T_c$ superconductivity in iron-based
compounds has prompted an intensive investigation on the role of interaction
and magnetism in the these materials. Based on the general features of
multi-bands and intermediate coupling strengths, a phenomenological theory of
coexisting itinerant an... | 1311.4094v2 |
2014-01-14 | Unconventional superconductivity in iron-base superconductors in a three-band model | Iron-base superconductors exhibits features of systems where the
Fulde-Ferrel-Larkin-Ovchinnikov (FFLO) phase, a superconducting state with
non-zero total momentum of Cooper pairs, is actively sought. Experimental and
theoretical evidence points strongly to the FFLO phase in these materials above
the Pauli limit. In th... | 1401.3066v1 |
2014-02-28 | Antiferromagnetism in Iron-Based Superconductors: Selection of Magnetic Order and Quasiparticle Interference | The recent discovery of superconductivity in the iron-based layered pnictides
with T_c ranging between 26 and 56K generated enormous interest in the physics
of these materials. Here, we review some of the peculiarities of the
antiferromagnetic order in the iron pnictides, including the selection of the
stripe magnetic ... | 1402.7206v1 |
2014-08-18 | Relativistic configuration-interaction calculation of $Kα$ transition energies in beryllium-like iron | We perform relativistic configuration-interaction calculations of the energy
levels of the low-lying and core-excited states of beryllium-like iron,
Fe$^{22+}$. The results include the QED contributions calculated by two
different methods, the model QED operator approach and the screening-potential
approach. The uncert... | 1408.3949v1 |
2015-05-19 | Electromagnetic acceleration of permanent magnets | We consider the acceleration of the permanent magnets, consisting of
neodymium iron boron by means of the running magnetic field gradient. It is
shown that the specific magnetic moment per nucleon in neodymium iron boron is
determined by the remained magnetization of the substance. The maximum
accessable gradient of th... | 1508.04078v1 |
2016-02-17 | On the analysis of stage I in the resistivity recovery of electron irradiated iron | The experimental results of Takaki et al. [1] on the stage I resistivity
recovery of electron irradiated iron are analyzed using the analytical theory
of diffusion annealing formulated by Simpson & Sossin [2] and Schroeder [3]
taking into account the recent first-principles calculations of Fu et al. [4]
regarding the m... | 1602.05449v2 |
2017-09-11 | Magnetic order and phase transition in the iron oxysulfide La2O2Fe2OS2 | The Mott-insulating iron oxychalcogenides exhibit complex magnetic behaviour
and we report here a neutron diffraction investigation into the magnetic
ordering in La2O2Fe2OS2. This quaternary oxysulfide adopts the
anti-Sr2MnO2Sb2-type structure and orders antiferromagnetically below TN = 105
K. We consider both its long... | 1709.03323v1 |
2018-03-05 | Using electron irradiation to probe iron - based superconductors | High energy electron irradiation is an efficient way to create
vacancy-interstitial Frenkel pairs in crystal lattice, thereby inducing
controlled non-magnetic point - like scattering centers. In combination with
London penetration depth and resistivity measurements, the irradiation was
particularly useful as a phase - ... | 1803.01956v1 |
2019-03-30 | Shot Noise as a probe for the pairing symmetry of Iron pnictide superconductors | One of the outstanding problems in Iron pnictide research is the unambiguous
detection of its pairing symmetry. The most probable candidates are the
two-band s$++$ and sign reversed s$\pm$ wave pairing. In this work, the Andreev
conductance and shot noise are used as a probe for the pairing symmetry of Iron
pnictide su... | 1904.00201v2 |
2022-04-07 | Editorial on Research Topic: High-Tc Superconductivity in Electron-Doped Iron Selenide and Related Compounds | In this editorial, we first give a brief survey of the field of iron-selenide
superconductivity, both in the case of bulk FeSe characterized by the
co-existence of superconductivity and nematic order, and in the case of
electron-doped FeSe characterized by high-temperature superconductivity. We
next review the 8 contri... | 2204.03735v2 |
2022-08-25 | Persistent homology analysis with nonnegative matrix factorization for 3D voxel data of iron ore sinters | This paper proposes a data analysis method using persistent homology and
nonnegative matrix factorization. A concatenated persistence image technique is
used to extract coexisting structures from the persistence diagrams of
different dimensions hidden behind the data. To demonstrate the potential of
our method, we appl... | 2208.11943v1 |
2023-02-20 | Triplet pairing, orbital selectivity and correlations in Iron-based superconductors | We use a slave-boson approach to study the band renormalization and pair
susceptibility in the normal state of Iron-based superconductors in presence of
strong Coulomb repulsion and Hund's interaction. Our results show orbital
selectivity toward localization of $xy$ orbitals and its interplay with
superconductivity. We... | 2302.09702v1 |
1996-07-03 | ASCA observations of the iron K complex of Circinus X-1 near zero phase: spectral evidence for partial covering | We report on ASCA energy spectra of Cir X-1 taken near its zero phase on 1994
August 4-5. The ASCA SIS detectors allow a more detailed study of the iron K
complex than has been possible before. We find that prior to a sudden upward
flux transition the dominant iron K feature appears to consist of a large edge
from neut... | 9607018v1 |
1997-05-19 | Iron fluorescence from within the innermost stable orbit of black hole accretion disks | The fluorescent iron Ka line is a powerful observational probe of the inner
regions of black holes accretion disks. Previous studies have assumed that only
material outside the radius of marginal stability can contribute to the
observed line emission. Here, we show that fluorescence by material inside the
radius of mar... | 9705136v2 |
2002-02-22 | The continuum variability of MCG--6-30-15: A detailed analysis of the long 1999 ASCA observation | We report on an analysis in the 3--10 keV X-ray band of the long 1999 ASCA
observation of MCG--6-30-15. The time-averaged broad iron K line is
well-described by disk emission near a Schwarzschild black hole, confirming the
results of earlier analyses on the ASCA 1994 and 1997 data. The time-resolved
iron-line profile i... | 0202432v1 |
2002-09-09 | The X-ray spectrum of the Seyfert I galaxy Mrk 766: Dusty Warm Absorber or Relativistic Emission Lines? | Competing models for broad spectral features in the soft X-ray spectrum of
the Seyfert I galaxy Mrk766 are tested against data from a 130 ks XMM-Newton
observation. A model including relativistically broadened Ly-alpha emission
lines of OVIII, NVII and CVI is a better fit to 0.3-2 keV XMM RGS data than a
dusty warm abs... | 0209145v1 |
2005-11-19 | Thermal X-Ray Iron Line Emission from the Galactic Center Black Hole Sagittarius A* | We model thermal X-ray emission from the accreting supermassive black hole
Sagittarius A* at the Galactic Center. For the region inside
$1.^{\prime\prime}5$ of the center, we use a {generalized} radiatively
inefficient accretion flow (RIAF) model, and for the region out to
$10^{\prime\prime}$ we use published models of... | 0511590v1 |
2006-06-23 | Fe-bump instability: the excitation of pulsations in subdwarf B and other low-mass stars | We consider the excitation of radial and non-radial oscillations in low-mass
B stars by the iron-bump opacity mechanism. The results are significant for the
interpretation of pulsations in subdwarf B stars, helium-rich subdwarfs and
extreme helium stars, including the EC14026 and PG1716 variables. We
demonstrate that, ... | 0606594v2 |
2008-03-03 | Constraints on grain size and stable iron phases in the uppermost Inner Core from multiple scattering modeling of seismic velocity and attenuation | We propose to model the uppermost inner core as an aggregate of randomly
oriented anisotropic ``patches''. A patch is defined as an assemblage of a
possibly large number of crystals with identically oriented crystallographic
axes. This simple model accounts for the observed velocity isotropy of short
period body waves,... | 0803.0264v1 |
2008-06-24 | A BLR origin for the iron K$α$ line in NGC7213 | The X-ray spectrum of NGC7213 is known to present no evidence for Compton
reflection, a unique result among bright Seyfert 1s. The observed neutral iron
K$\alpha$ line, therefore, cannot be associated with a Compton-thick material,
like the disc or the torus, but is due to Compton-thin gas, with the Broad Line
Region (... | 0806.3876v1 |
2008-08-04 | Iron pnictides as a new setting for quantum criticality | Two major themes in the physics of condensed matter are quantum critical
phenomena and unconventional superconductivity. These usually occur in the
context of competing interactions in systems of strongly-correlated electrons.
All this interesting physics comes together in the behavior of the recently
discovered iron p... | 0808.0305v3 |
2008-09-18 | A search for iron emission lines in the Chandra X-ray spectra of neutron star low-mass X-ray binaries | While iron emission lines are well studied in black hole systems, both in
X-ray binaries and Active Galactic Nuclei, there has been less of a focus on
these lines in neutron star low-mass X-ray binaries (LMXBs). However, recent
observations with Suzaku and XMM-Newton have revealed broad asymmetric iron
line profiles in... | 0809.3171v1 |
2009-04-01 | The nature of the light variability of the silicon star HR 7224 | Although photometric variations of chemically peculiar (CP) stars are
frequently used to determine their rotational periods, the detailed mechanism
of their light variability remains poorly understood. We simulate the light
variability of the star HR 7224 using the observed surface distribution of
silicon and iron. We ... | 0904.0231v1 |
2011-01-03 | Thermal X-ray iron line emission from the advection dominated accretion flow in the galactic binary GX 339-4 | We explore thermal X-ray iron line emission from the galactic X-ray binary GX
339-4 in the off state, using the models of the advection dominated accretion
flow (ADAF) without or with outflows. The equivalent widths of hydrogen-like
and helium-like thermal iron lines are calculated with different model
parameters inclu... | 1101.0507v1 |
2011-08-24 | The effects of aggregation and protein corona on the cellular internalization of iron oxide nanoparticles | Engineered inorganic nanoparticles are essential components in the
development of nanotechnologies. For applications in nanomedicine, particles
need to be functionalized to ensure a good dispersibility in biological fluids.
In many cases however, functionalization is not sufficient : the particles
become either coated ... | 1108.4779v1 |
2011-09-02 | A first-principles study of helium storage in oxides and at oxide--iron interfaces | Density-functional theory calculations based on conventional as well as
hybrid exchange-correlation functionals have been carried out to study the
properties of helium in various oxides (Al2O3, TiO2, Y2O3, YAP, YAG, YAM, MgO,
CaO, BaO, SrO) as well as at oxide-iron interfaces. Helium interstitials in
bulk oxides are sh... | 1109.0433v2 |
2012-08-21 | Evolution of precipitate morphology during heat treatment and its implications for the superconductivity in KxFe1.6+ySe2 single crystals | We study the relationship between precipitate morphology and
superconductivity in KxFe1.6+ySe2 single crystals grown by self-flux method.
Scanning electron microscopy (SEM) measurements revealed that superconducting
phase forms a network in the samples quenched above iron vacancy order-disorder
transition temperature T... | 1208.4159v2 |
2012-10-24 | The Unexpected Properties of Alkali Metal Iron Selenide Superconductors | The iron-based superconductors that contain FeAs layers as the fundamental
building block in the crystal structures have been rationalized in the past
using ideas based on the Fermi Surface nesting of hole and electron pockets
when in the presence of weak Hubbard $U$ interactions. This approach seemed
appropriate consi... | 1210.6501v1 |
2013-02-08 | X-ray diagnostics of chemical composition of the accretion disk and donor star in ultra-compact X-ray binaries | Non-solar composition of the donor star in ultra-compact X-ray binaries may
have a pronounced effect on the fluorescent lines appearing in their spectra
due to reprocessing of primary radiation by the accretion disk and the white
dwarf surface. We show that the most dramatic and easily observable consequence
of the ano... | 1302.2070v2 |
2013-03-26 | Superconductivity and Crystal Structure of the Palladium-Iron-Arsenides Ca10(Fe1-xPdxAs)10Pd3As8 | The palladium-iron-arsenides Ca10(Fe1-xPdxAs)10(Pd3As8) were synthesized by
solid state methods and characterized by X-ray powder and single crystal
diffraction. The triclinic crystal structure (space group P-1) is isotypic to
the homologue platinum 1038 type superconductors with alternating FeAs4/4- and
Pd3As8-layers,... | 1303.6579v1 |
2013-05-22 | Iron abundance correlations and an occurrence distribution discrepancy from ongoing planet migration | Whether the higher occurrence of giant planets being hosted by metal-rich
versus metal-poor stars results from formation or from "pollution" has been a
question of intense debate. We present new patterns that emerge when
planet/star systems are separated by stellar [Fe/H], and when systems with
stellar companions are s... | 1305.5197v2 |
2013-11-05 | Spin dynamics and an orbital-antiphase pairing symmetry in iron-based superconductors | The symmetry of the wave function describing the Cooper pairs is one of the
most fundamental quantities in a superconductor but its measurement in the
iron-based superconductors has proved to be very difficult. The complex
multi-band nature of these materials makes the interplay of superconductivity
with spin and orbit... | 1311.1188v1 |
2013-12-04 | Mössbauer studies of the peculiar magnetism in parent compounds of the iron-based superconductors | A review of the magnetism in the parent compounds of the iron-based
superconductors is given based on the transmission Moessbauer spectroscopy of
57Fe and 151Eu. It was found that the 3d magnetism is of the itinerant
character with varying admixture of the spin-polarized covalent bonds. For the
122 compounds a longitud... | 1312.1152v1 |
2014-02-25 | C/O abundance ratios, iron depletions, and infrared dust features in Galactic planetary nebulae | We study the dust present in 56 Galactic planetary nebulae (PNe) through
their iron depletion factors, their C/O abundance ratios (in 51 objects), and
the dust features that appear in their infrared spectra (for 33 objects). Our
sample objects have deep optical spectra of good quality, and most of them also
have ultrav... | 1402.6376v1 |
2014-12-12 | Electronic structure of ruthenium-doped iron chalcogenides | The structural and electronic properties of hypothetical Ru$_x$Fe$_{1-x}$Se
and Ru$_x$Fe$_{1-x}$Te systems have been investigated from first principles
within the density functional theory (DFT). Reasonable values of lattice
parameters and chalcogen atomic positions in the tetragonal unit cell of iron
chalcogenides hav... | 1412.3961v1 |
2015-04-08 | Testing the Kerr Nature of Black Hole Candidates using Iron Line Spectra in the CPR Framework | The iron K$\alpha$ line commonly observed in the X-ray spectrum of both
stellar-mass and supermassive black hole candidates originates from X-ray
fluorescence of the inner accretion disk. Accordingly, it can be used to map
the spacetime geometry around these objects. In this paper, we extend previous
work using the iro... | 1504.01970v2 |
2015-06-10 | Structural disorder in Li(x)[C5H5N](y)Fe(2-z)Se2 and Cs(x)Fe(2-z)Se2 superconductors studied by Mössbauer spectroscopy | Two iron-chalcogenide superconductors Li(x)[C5H5N](y)Fe(2-z)Se2 and
Cs(x)Fe(2-z)Se2 in the as-prepared and annealed state have been investigated by
means of the Moessbauer spectroscopy versus temperature. Multi-component
spectra are obtained. One can see a non-magnetic component due to iron located
in the unperturbed F... | 1506.03390v2 |
2015-12-02 | The iron dispersion of the globular cluster M 2, revised | M 2 has been claimed to posses three distinct stellar components that are
enhanced in iron relative to each other. We use equivalent width measurements
from 14 red giant branch stars from which Yong et al. detect a $\sim$0.8 dex
wide, trimodal iron distribution to redetermine the metallicity of the cluster.
In contrast... | 1512.00691v1 |
2016-02-16 | Role of Arsenic in Iron-based Superconductivity at Atomic Scale | In iron-based superconductors, a unique tri-layer Fe-As (Se, Te, P) plays an
essential role in controlling the electronic properties, especially the Cooper
pairing interaction. Here we use scanning tunneling microscopy/spectroscopy
(STM/S) to investigate the role of arsenic atom in superconducting
Ba0.4K0.6Fe2As2 by di... | 1602.04956v2 |
2016-08-03 | High-temperature miscibility of iron and rock during terrestrial planet formation | The accretion of a terrestrial body and differentiation of its silicate/oxide
mantle from iron core provide abundant energy for heating its interior to
temperatures much higher than the present day Earth. The consequences of
differentiation on the structure and composition of planets are typically
addressed considering... | 1608.01295v1 |
2017-11-27 | Solar abundance ratios of the iron-peak elements in the Perseus Cluster | The metal abundance of the hot plasma that permeates galaxy clusters
represents the accumulation of heavy elements produced by billions of
supernovae. Therefore, X-ray spectroscopy of the intracluster medium provides
an opportunity to investigate the nature of supernova explosions integrated
over cosmic time. In partic... | 1711.10035v1 |
2017-12-15 | Tunable polymorphism of epitaxial iron oxides in the four-in-one ferroic-on-GaN system with magnetically ordered α-, γ-, ε-Fe2O3 and Fe3O4 layers | Hybridization of semiconducting and magnetic materials into a single
heterostructure is believed to be potentially applicable to the design of novel
functional spintronic devices. In the present work we report epitaxial
stabilization of four magnetically ordered iron oxide phases (Fe3O4,
{\gamma}-Fe2O3, {\alpha}-Fe2O3 ... | 1712.05632v1 |
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