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2024-01-04 | Effect of Ca doping on Li ion conductivity of Ge and Ta doped garnet LLZO | The series Li6.55+xGe0.05La3-xCaxZr1.75Ta0.25O12 ( x= 0, 0.05, 0.10, 0.15,
0.20 ) was prepared by conventional solid state reaction method with the
sintering temperature of 10500C for 7.30 hr by substituting Ca at the La site
to increase the Li ion conductivity. The synergistic effects of Ca
incorporation on Li6.55Ge0.... | 2401.02359v1 |
2024-01-23 | Tensor network influence functionals in the continuous-time limit: connections to quantum embedding, bath discretization, and higher-order time propagation | We describe two developments of tensor network influence functionals (in
particular, influence functional matrix product states (IF-MPS)) for quantum
impurity dynamics within the fermionic setting of the Anderson impurity model.
The first provides the correct extension of the IF-MPS to continuous time by
introducing a ... | 2401.12460v1 |
2024-02-19 | Image Super-resolution Inspired Electron Density Prediction | Drawing inspiration from the domain of image super-resolution, we view the
electron density as a 3D grayscale image and use a convolutional residual
network to transform a crude and trivially generated guess of the molecular
density into an accurate ground-state quantum mechanical density. We find that
this model outpe... | 2402.12335v1 |
2024-02-27 | Fast Lithium Ion Diffusion in Brownmillerite $\mathrm{Li}_{x}\mathrm{{Sr}_{2}{Co}_{2}{O}_{5}}$ | Ionic conductors have great potential for interesting tunable physical
properties via ionic liquid gating and novel energy storage applications such
as all-solid-state lithium batteries. In particular, low migration barriers and
high hopping attempt frequency are the keys to achieve fast ion diffusion in
solids. Taking... | 2402.17557v2 |
2024-04-02 | Understanding spin currents from magnon dispersion and polarization: Spin-Seebeck effect and neutron scattering study on Tb3Fe5O12 | Magnon spin currents in the ferrimagnetic garnet Tb3Fe5O12 with 4f electrons
were examined through the spin-Seebeck effect and neutron scattering
measurements. The compound shows a magnetic compensation, where the
spin-Seebeck signal reverses above and below Tcomp = 249.5(4) K. Unpolarized
neutron scattering unveils tw... | 2404.01603v1 |
2024-04-04 | Performant Automatic Differentiation of Local Coupled Cluster Theories: Response Properties and Ab Initio Molecular Dynamics | In this work, we introduce a differentiable implementation of the local
natural orbital coupled cluster (LNOCC) method within the automatic
differentiation framework of the PySCFAD package. The implementation is
comprehensively tuned for enhanced performance, which enables the calculation
of first-order static response... | 2404.03129v2 |
1998-03-17 | The Soft X-ray Spectrum of Scattering--Dominated AGN | This paper discusses the properties of scattering--dominated active galactic
nuclei (AGN). We define these to be AGN for which the direct line-of-sight to
the continuum source is obscured by Compton-thick material. The aim is to
construct, for the first time, a model consistent with X-ray line luminosities,
line ratios... | 9803205v1 |
2001-06-15 | The effects of relativistic bulk motion of X-ray flares in the corona on the iron Kalpha line in Seyfert 1 galaxies | We study the effects of the bulk motion of X-ray flares on the shape and
equivalent width of the iron Kalpha line from an untruncated cold disk around a
Kerr black hole using fully relativistic calculations. The flares are located
above a cold accretion disk -- either on or off the rotation axis. For on- or
off-axis fl... | 0106290v2 |
2004-10-20 | The impact of non-LTE effects and granulation inhomogeneities on the derived iron and oxygen abundances in metal-poor halo stars | This paper presents the results of a detailed theoretical investigation of
the impact of non-LTE effects and of granulation inhomogeneities on the derived
iron and oxygen abundances in the metal-poor halo subgiant HD140283. Our
analysis is based on both the `classical' one-dimensional (1D) stellar
atmosphere models and... | 0410475v1 |
2005-03-29 | The XMM-Newton view of Mrk3 and IXO30 | We present the analysis of the XMM-Newton EPIC pn spectrum of the Seyfert 2
galaxy, Mrk3. We confirm that the source is dominated by a pure Compton
reflection component and an iron K$\alpha$ line, both produced as reflection
from a Compton-thick torus, likely responsible also for the large column
density which is pierc... | 0503623v1 |
2007-05-30 | Numerical Study on Stellar Core Collapse and Neutrino Emission: Probe into the Spherically Symmetric Black Hole Progenitors with 3 - 30Msun Iron Cores | The existence of various anomalous stars, such as the first stars in the
universe or stars produced by stellar mergers, has been recently proposed. Some
of these stars will result in black hole formation. In this study, we
investigate iron core collapse and black hole formation systematically for the
iron-core mass ran... | 0705.4350v1 |
2011-05-24 | Spin Waves and magnetic exchange interactions in insulating Rb$_{0.89}$Fe$_{1.58}$Se$_2$ | The discovery of alkaline iron selenide $A$Fe$_{1.6+x}$Se$_2$ ($A=$ K, Rb,
Cs) superconductors has generated considerable excitement in the condensed
matter physics community because superconductivity in these materials may have
a different origin from the sign reversed s-wave electron pairing mechanism, a
leading cand... | 1105.4675v1 |
2012-10-08 | Magnetic fluctuations and effective magnetic moments in γ-iron due to electronic structure peculiarities | Applying the local density and dynamical mean field approximations to
paramagnetic \gamma-iron we revisit the problem of theoretical description of
magnetic properties in a wide temperature range. We show that contrary to
\alpha-iron, the frequency dependence of the electronic self-energy has a
quasiparticle form for b... | 1210.2188v2 |
2012-10-18 | Electron Correlation and Spin Dynamics in Iron Pnictides and Chalcogenides | Superconductivity in the iron pnictides and chalcogenides is closely
connected to a bad-metal normal state and a nearby antiferromagnetic order.
Therefore, considerable attention has been focused on the role of electron
correlations and spin dynamics. In this article, we summarize some key
experiments that quite direct... | 1210.5017v2 |
2014-02-06 | A single low-energy, iron-poor supernova as the source of metals in the star SMSS J 031300.36-670839.3 | The element abundance ratios of four low-mass stars with extremely low
metallicities indicate that the gas out of which the stars formed was enriched
in each case by at most a few, and potentially only one low-energy, supernova.
Such supernovae yield large quantities of light elements such as carbon but
very little iro... | 1402.1517v1 |
2015-04-09 | A three-dimensional hydrodynamical line profile analysis of iron lines and barium isotopes in HD140283 | Heavy-elements, i.e. those beyond the iron peak, mostly form via two neutron
capture processes: the s- and r-process. Metal-poor stars should contain fewer
isotopes that form via the s-process, according to currently accepted theory.
It has been shown in several investigations that theory and observation do not
agree w... | 1504.02353v1 |
2015-06-12 | Identification of prototypical Brinkman-Rice Mott physics in a class of iron chalcogenides superconductors | The 122$^{*}$ series of iron-chalcogenide superconductors, for example
K$_x$Fe$_{2-y}$Se$_{2}$, only possesses electron Fermi pockets. Their
distinctive electronic structure challenges the picture built upon iron
pnictide superconductors, where both electron and hole Fermi pockets coexist.
However, partly due to the in... | 1506.04018v3 |
2015-11-30 | Iron Fluorescent Line Emission from the mCvs and Hard X-ray Emitting Symbiotic Stars as a Source of the Iron Fluorescent Line Emission from the Galactic Ridge | The Galactic Ridge X-ray Emission (GRXE) spectrum has strong iron emission
lines at 6.4, 6.7, and 7.0~keV, each corresponding to the neutral (or
low-ionized), He-like, and H-like iron ions. The 6.4~keV fluorescence line is
due to irradiation of neutral (or low ionized) material (iron) by hard X-ray
sources, indicating ... | 1511.09424v2 |
2016-06-16 | Broadband X-ray emission and the reality of the broad iron line from the Neutron Star - White Dwarf X-ray binary 4U 1820-30 | Broad relativistic iron lines from neutron star X-ray binaries are important
probes of the inner accretion disk. The X-ray reflection features can be
weakened due to strong magnetic fields or very low iron abundances such as is
possible in X-ray binaries with low mass, first generation stars as companions.
Here we inve... | 1606.05307v1 |
2020-01-09 | Near-ultraviolet Transmission Spectroscopy of HD 209458b: Evidence of Ionized Iron Beyond the Planetary Roche Lobe | The inflated transiting hot Jupiter HD 209458b is one of the best studied
objects since the beginning of exoplanet characterization. Transmission
observations of this system between the mid infrared and the far ultraviolet
have revealed the signature of atomic, molecular, and possibly aerosol species
in the lower atmos... | 2001.03126v1 |
2020-03-22 | Formation of embryos of the Earth and the Moon from the common rarefied condensation and their subsequent growth | Embryos of the Moon and the Earth may have formed as a result of contraction
of a common parental rarefied condensation. The required angular momentum of
this condensation could largely be acquired in a collision of two rarefied
condensations producing the parental condensation. With the subsequent growth
of embryos of... | 2003.09925v1 |
2020-07-01 | Cobalt and copper abundances in 56 Galactic bulge red giants | The Milky Way bulge is an important tracer of the early formation and
chemical enrichment of the Galaxy. The abundances of different iron-peak
elements in field bulge stars can give information on the nucleosynthesis
processes that took place in the earliest supernovae. Cobalt (Z=27) and copper
(Z=29) are particularly ... | 2007.00397v1 |
2021-05-23 | Decomposing the Iron Cross-Correlation Signal of the Ultra-Hot Jupiter WASP-76b in Transmission using 3D Monte-Carlo Radiative Transfer | Ultra-hot Jupiters are tidally locked gas giants with dayside temperatures
high enough to dissociate hydrogen and other molecules. Their atmospheres are
vastly non-uniform in terms of chemistry, temperature and dynamics, and this
makes their high-resolution transmission spectra and cross-correlation signal
difficult to... | 2105.11034v2 |
2021-07-13 | How many explosions does one need? -- Quantifying supernovae in globular clusters from iron abundance spreads | Many globular clusters (GCs) are known to host multiple populations
distinguishable by their light-element content. Less common are GCs displaying
iron abundance spreads which are seen as evidence for enrichment through core
collapse supernovae (SNe). We present a simple analytical method to estimate
the number of SNe ... | 2107.06240v3 |
2021-11-22 | Chemo-Mechanical Phase-Field Modeling of Iron Oxide Reduction with Hydrogen | The reduction of iron ore with carbon-carriers is one of the largest sources
of greenhouse gas emissions in the industry, motivating global activities to
replace the coke-based blast furnace reduction by hydrogen-based direct
reduction (HyDR). Iron oxide reduction with hydrogen has been widely
investigated both experim... | 2111.11538v1 |
2021-11-30 | A New Iron Emission Template for Active Galactic Nuclei. I. Optical Template for the H$β$ region | We present a new empirical template for iron emission in active galactic
nuclei (AGN) covering the $4000-5600$ A range. The new template is based on a
spectrum of the narrow-line Seyfert 1 galaxy Mrk 493 obtained with the Hubble
Space Telescope. In comparison with the canonical iron template object I Zw 1,
Mrk 493 has ... | 2111.15118v2 |
2022-10-03 | Physical Modeling of Dust Polarization from Magnetically Enhanced Radiative Torque (MRAT) Alignment in Protostellar Cores with POLARIS | Magnetic fields ($\textbf{B}$) are an important factor that controls the star
formation process. The leading method to observe $\textbf{B}$ is using
polarized thermal emission from dust grains aligned with $\textbf{B}$. However,
in dense environments such as protostellar cores, dust grains may have
inefficient alignmen... | 2210.01036v3 |
2022-10-05 | The magnetic properties of the iron phthalocyanine molecule grafted to the Ti$_2$C MXene layer | The magnetic tetrapyrrole molecules (such as porphyrins and phthalocyanines)
with an active transition metal atom in their centre are currently intensively
studied as prosperous potential elements of devices for high-density
information storage and processing. It has been recently proved that by means
of external facto... | 2210.02141v1 |
2022-12-07 | Nodal s$_\pm$ Pairing Symmetry in an Iron-Based Superconductor with only Hole Pockets | The origin of the high temperature superconductivity in the iron-based
superconductors remains elusive after being extensively studied for more than a
decade. Determination of the pairing symmetry is essential in understanding the
superconductivity mechanism. In the iron-based superconductors that have hole
pockets aro... | 2212.03472v1 |
2023-03-20 | Machine learning assisted phase and size-controlled synthesis of iron oxides | The controllable synthesis of iron oxides particles is a critical issue for
materials science, energy storage, biomedical applications, environmental
science, and earth science. However, synthesis of iron oxides with desired
phase and size are still a time-consuming and trial-and-error process. This
study presents solu... | 2303.11244v1 |
1997-02-17 | Lack of Evolution in the Iron Abundance in Clusters of Galaxies and Implications for the Global Star Formation Rate at High Redshift | We present the first large sample of accurate iron abundances and
temperatures for clusters at redshifts greater than 0.14. We find that the Fe
abundance shows little or no evolution out to redshift 0.3. This and the early
formation epoch of elliptical galaxies in clusters indicate that most of the
enrichment of the in... | 9702149v1 |
1997-02-21 | Reply to ``Roles of SNIa and SNII in ICM Enrichment'' by Y. Ishimaru and N. Arimoto | We address a number of misunderstandings and misstatements contained in the
paper ``Roles of SNIa and SNII in ICM Enrichment'' by Y. Ishimaru and N.
Arimoto with regard to the papers by Mushotzky et al. (1996, ApJ, 466, 686) and
Loewenstein and Mushotzky (1996, ApJ, 466, 695). In particular, we emphasize
that compariso... | 9702190v1 |
1998-02-03 | Iron Kalpha line widths in magnetic cataclysmic variables | Following a recent report that AO Psc has broad iron Kalpha emission lines we
have looked at the ASCA spectra of 15 magnetic cataclysmic variables. We find
that half of the systems have Kalpha lines broadened by ~200 eV, while the
remainder have narrow lines. We argue that the Doppler effect is insufficient
to explain ... | 9802040v1 |
1998-05-19 | Multi-Element Doppler Imaging of the Ap star epsilon Ursae Majoris | The surface distribution of five elements: iron, chromium, titanium,
magnesium and manganese on the magnetic A0pCr star epsilon UMa, have been
calculated using the Doppler imaging technique. We found that iron, chromium
and manganese are correlated with the assumed dipole magnetic field geometry of
this star, which is ... | 9805244v1 |
1998-10-30 | Spinning Black Holes in Active Galactic Nuclei | Recent X-ray spectroscopy made with ASCA have shown broad, skewed iron line
emission from Seyfert-1 galaxies. The large extent of the red tail allows
probing of the innermost regions of the black hole's accretion disc. A model of
line emission has been developed and very strong evidence for the presence of a
rapidly ro... | 9810494v1 |
2000-11-10 | The formation of life | The formation of life is an automatic stage in the consolidation of rocky or
"terrestrial" planets. The organic (=carbonaceous) matter, light elements,
gases, and water must "float" toward the surface and the heavier metals must
sink toward the center. Random processes in the molecular soup that fills
microfractures in... | 0011209v1 |
2001-09-17 | Iron line profiles from black hole accretion discs with spiral velocity structure | We calculate the iron line profiles from accretion discs with spiral velocity
structures around Schwarzschild black holes. We find that quasi-periodic bumps
appear in the the profiles, thereby providing a test for spiral wave patterns.
This study is motivated by recent work showing that spiral density waves can
result ... | 0109243v1 |
2002-01-12 | On the origin of the broad, relativistic iron line of MCG-6-30-15 observed by XMM-Newton | The relativistic iron line profile recently observed by XMM-Newton in the
spectrum of the Seyfert 1 galaxy MCG--6-30-15 (Wilms et al., 2001) is discussed
in the framework of the lamp-post model. It is shown that the steep disc
emissivity, the large line equivalent width and the amount of Compton
reflection can be self-... | 0201192v1 |
2002-01-17 | FUSE observations of the central star of Abell 78 | FUSE high resolution spectra of two PG1159 type central stars (K1-16 and NGC
7094) have revealed an unexpected iron deficiency of at least 1 or 2 dex (Miksa
et al. 2002). Here we present early results of FUSE spectroscopy of the CSPN
Abell 78. It is shown that iron is strongly deficient in this star, too. | 0201280v1 |
2002-02-07 | Fe-deficiency in H-deficient post-AGB stars due to n-capture nucleosynthesis | H-deficient post-AGB objects, e.g. PG1159 type star K1-16 and born-again AGB
star Sakurai's object, have been reported to be significantly iron-deficient.
We find that the iron deficiencies expected due to neutron-capture
nucleosynthesis during either the progenitor AGB evolution and/or the neutron
burst that occurs as... | 0202143v1 |
2002-08-28 | Metal abundances in PG1159 stars from Chandra and FUSE spectroscopy | We investigate FUSE spectra of three PG1159 stars and do not find any
evidence for iron lines. From a comparison with NLTE models we conclude a
deficiency of 1-1.5 dex. We speculate that iron was transformed into heavier
elements. A soft X-ray Chandra spectrum of the unique H- and He-deficient star
H1504+65 is analyzed... | 0208505v1 |
2002-11-06 | Iron abundances in hydrodynamical simulations of galaxy clusters | Hydrodynamical SPH simulations of galaxy clusters are used to investigate the
metal enrichment of the intracluster medium. The final metallicity abundances
of the simulated clusters are determined according to the numerical resolution
and a number of model parameters. For a fiducial set of model prescriptions the
resul... | 0211111v1 |
2003-02-18 | The recent X-ray history of NGC 5506 | We present a detailed discussion of the spectral and spatial components of
NGC 5506, based on XMM-Newton, Chandra and BeppoSAX observations. The overall
picture consists of a nucleus absorbed by cold gas with column density of
$\approx10^{22}$ cm$^{-2}$ and surrounded by a Compton-thick torus, whose
existence is inferr... | 0302349v1 |
2003-11-03 | Iron Emission in z ~ 6 QSOs and its Possible Implications | We have obtained low-resolution near-infrared spectra of five SDSS QSOs at
5.3 < z < 6.3 using the NICMOS instrument of the Hubble Space Telescope. We
find evidence of emission in the Fe II complex centered near 2500 A (rest) in
all five objects. We estimate Fe II / Mg II 2800 A flux ratios comparable to
those measured... | 0311043v1 |
2004-02-12 | Accurate Modelling of Relativistic Iron Lines from Accretion Discs | Observations of fluorescent iron lines from accreting black holes provide one
of the best tests of strong field gravity available to date, and the only
current observational tool to probe black hole spacetime. However, the two most
widely used models for spectral fitting (diskline, laor) are over a decade old
and have ... | 0402279v1 |
2004-06-10 | The sharp drop in the flux striking the accretion disk | In this paper,We present a simple relativistic approach to analyze the flux
striking the disk which is possibly from a source up the Black hole.The X-ray
source is locate above an accretion disc orbiting around the black hole,this
assumption is invoked by recent studies about iron k$\alpha$. we compute and
arguing that... | 0406258v1 |
2004-10-29 | Chemical abundances of RGB-Tip stars in the Sagittarius dwarf Spheroidal galaxy | We present preliminary iron abundances and $\alpha$ element (Ca, Mg)
abundance ratios for a sample of 22 Red Giant Branch (RGB) Stars in the
Sagittarius dwarf spheroidal galaxy (Sgr), selected near the RGB-Tip. The
sample is representative of the Sgr dominant population. The mean iron
abundance is [Fe/H]=-0.49. The $\a... | 0410749v1 |
2004-11-06 | Surface Evidence of an Iron-Rich Solar Interior and a Neutron-Rich Solar Core | Quantitative data on the solar wind, solar magnetic fields, solar eruptions,
solar neutrinos, and on the planetary material orbiting the Sun all indicate
the presence of an iron-rich solar interior and a neutron star at the core of
the Sun. Solar magnetic fields are deep-seated remnants from the core and/or
Bose-Einste... | 0411163v1 |
2005-01-31 | Resonant Auger Destruction and Iron K-Alpha Spectra in Compact X-ray Sources | We examine the effects of resonant Auger destruction in modifying the
intensities and flux distributions of K-alpha spectra from iron L-shell ions.
Applications include X-ray irradiated stellar winds in X-ray binaries and
accretion disk atmospheres. Using detailed atomic models, we find that resonant
Auger destruction ... | 0502002v1 |
2007-01-24 | Photospheric magnetic field and chromospheric emission | We present a statistical analysis of network and internetwork properties in
the photosphere and the chromosphere. For the first time we simultaneously
observed (a) the four Stokes parameters of the photospheric iron line pair at
630.2 nm and (b) the intensity profile of the Ca II H line at 396.8 nm. The
vector magnetic... | 0701681v1 |
1996-02-11 | Theory on the Itinerant Ferromagnetism in the $3d$-transition metal systems | Keeping nickel, cobalt and iron in mind, we investigate the origin of the
itinerant ferromagnetism. In so doing, we generalize the Gutzwiller
approximation. In that,we take account of the effect of the band degeneracy and
the Hund's-rule coupling in addition to the on-site repulsion. After the
discussion on nickel, the... | 9602058v1 |
1999-12-14 | Hall cross size scaling and its application to measurements on nanometer-size iron particle arrays | Hall crosses were used to measure the magnetic properties of arrays of
ferromagnetic, nanometer-scale iron particles. The arrays typically consist of
several hundred particles of 9 -- 20 nm in diameter. It is shown that the
sensitivity of the measurements can be improved by matching the areas of the
Hall cross and the ... | 9912266v1 |
2000-08-15 | Electronic structure, hyperfine interactions and disordering effects in iron nitride Fe4N | Iron nitride Fe4N is studied by full-potential LAPW method. Structure
parameters, electronic and magnetic properties as well as hyperfine interaction
parameters are obtained. We observe perfect agreement with experimental
results. Hypothetical Fe4N structure was also calculated to study the influence
of disordering eff... | 0008214v1 |
2001-12-20 | Ferromagnetic and antiferromagnetic spin fluctuations and superconductivity in the hcp-phase of Fe | High purity iron, which transforms into the hcp phase under pressure, has
recently been reported to be superconducing in the pressure range 150-300 kBar
[shim]. The electronic structure and the electron-phonon coupling
($\lambda_{ph}$) are calculated for hcp iron at different volumes. A
parameter-free theory for calcul... | 0112382v1 |
2002-05-29 | Influence of nonstoichiometry and iron doping on optical absorption in KNbO3 single crystal | Single crystals of KNbO3 and KNbO3 : Fe have been grown using the flux method
at various technological conditions. The investigations of optical absorption
of these crystals were carried out. Marked influence of technological
conditions and doping with iron on optical absorption has been found. Observed
changes of the ... | 0205611v1 |
2002-11-12 | Magneto-Optical Kerr Effect of Iron Thin Films on Paramagnetic Substrates | First principles calculations of the magnetic properties and the
magneto-optical Kerr effect (MOKE) of iron thin films epitaxially grown on the
[001] surface of paramagnetic metals: copper, silver, gold, palladium, and
platinum are presented. The role of hybridization with the substrate is
investigated and it is shown ... | 0211234v1 |
2004-06-18 | First principles simulations of the magnetic and structural properties of Iron | We have implemented non-collinear GGA and a generalized Bloch's theorem to
simulate unconmensurate spiral arrangements of spins in a Density Functional
Theory code based on localized wave functions. We have subsequently performed a
thorough study of the different states of bulk Iron. We determine the minimal
basis set ... | 0406424v1 |
2004-07-27 | Composition dependent magnetic properties of iron oxide - polyaniline nanoclusters | Gamma - Iron Oxide prepared by sol -gel process was used to produce
nanocomposites with polyaniline of varying aniline concentrations. TEM shows
the presence of chain like structure for lower polyaniline concentration. The
room temperature hysteresis curves show finite coercivity of 160 Oe for all the
composites while ... | 0407693v1 |
2005-10-31 | Fe3O4(001) films on Fe(001) - termination and reconstruction of iron rich surfaces | High-quality and impurity-free magnetite surfaces with (sqrt2xsqrt2)R45o
reconstruction have been obtained for the Fe3O4(001) epitaxial films deposited
on Fe(001). Based on atomically resolved STM images for both negative and
positive sample polarity and Density Functional Theory calculations, a model of
the magnetite ... | 0510821v2 |
2006-06-16 | An iron(III) phosphonate cluster containing a nonanuclear ring | This communication reports the first example of cyclic ferric clusters with
an odd number of iron atoms capped by phosphonate ligands, namely,
[Fe9(m-OH)7(m-O)2(O3PC6H9)8-(py)12]. The magnetic studies support a S = 1/2
ground state with an exchange coupling constant of about J = -30 K. | 0606452v1 |
2006-12-12 | First-principles thermoelasticity of bcc iron under pressure | We investigate the elastic and isotropic aggregate properties of
ferromagnetic bcc iron as a function of temperature and pressure by computing
the Helmholtz free energies for the volume-conserving strained structures using
the first-principles linear response linear-muffin-tin-orbital method and the
generalized-gradien... | 0612308v1 |
2007-01-10 | Computational approach to finite size and shape effects in iron nanomagnets | We develop and validate a computational approach to nanomagnets. It is built
on the spin wave approximation to a Heisenberg ferromagnet whose parameters can
be calculated from a first principles theory (e.g. density functional theory).
The method can be used for high throughput analysis of a variety of
nanomagnetic mat... | 0701225v1 |
2007-02-05 | Theory of Layered Iron Oxide on Frustrated Geometry: Electric Polarization, Magnetoelectric Effect and Orbital State | A layered iron oxide \rfeo ($R$: rare-earth elements) is an exotic dielectric
material with charge-order (CO) driven electric polarization and
magnetoelectric effect caused by spin-charge coupling. In this paper, a theory
of electronic structure and dielectric property in \rfeo is presented. Charge
frustration in paire... | 0702087v2 |
1999-03-22 | Electron Response and e/h Ratio of Iron-Scintillator Hadron Prototype Calorimeter with Longitudinal Tile Configuration | The detailed information about electron response, electron energy resolution
and e/h ratio as a function of incident energy E, impact point Z and incidence
angle $\Theta$ of iron-scintillator hadron prototype calorimeter with
longitudinal tile configuration is presented. These results are based on
electron and pion bea... | 9903050v1 |
1999-03-22 | Non-Compensation of the Barrel Tile Hadron Module-0 Calorimeter | The detailed experimental information about the electron and pion responses,
the electron energy resolution and the e/h ratio as a function of incident
energy E, impact point Z and incidence angle $\Theta$ of the Module-0 of the
iron-scintillator barrel hadron calorimeter with the longitudinal tile
configuration is pre... | 9903054v1 |
2000-10-17 | Possible Observation of a Second Kind of Light | According to classical electrodynamics, sunlight that is passed through an
iron layer can be detected with the naked eye only if the thickness of the
layer is less than 170nm. However, in an old experiment, August Kundt was able
to see the sunlight with the naked eye even when it had passed an iron layer
with thickness... | 0010040v1 |
2003-01-10 | Modeling skin effect in large magnetized iron detectors | The experimental problem of the calibration of magnetic field in large iron
detectors is discussed. Emphasis is laid on techniques based on ballistic
measurements as the ones employed by MINOS or OPERA.In particular, we provide
analytical formulas to model the behavior of the apparatus in the transient
regime, keeping ... | 0301015v1 |
2004-01-26 | Local density and the RPA corrections in charge current quasielastic neutrino on Oxygen, Argon and Iron scattering | Numerical computations of cross sections for quasielastic charge current
scattering of neutrino on Oxygen, Argon and Iron in Local Density Approximation
(LDA) are presented. We consider processes for a few GeV neutrino energy. We
include corrections from nucleon re-interaction in nucleus described by
relativistic Rando... | 0401053v2 |
2007-04-13 | Towards understanding of birds magnetoreceptor mechanism | In the present letter we suggest a new theoretical model for a quantitative
description of the magnetoreception mechanism in birds. The considered
mechanism involves two types of iron minerals (magnetite and maghemite) which
were found in subcellular compartments within sensory dendrites of the upper
beak of several bi... | 0704.1763v1 |
2007-05-29 | A Challenge to Control Gravity via Applying Electromagnetic Low-Frequency Radiation - Theory and Proposed Model Experiments | Including Vaidya metric into the model of Expansive Nondecelerative Universe
allows to localize the energy of gravitational field. A term of effective
gravitational range is introduced and classic Newton potential is substituted
for Yukawa-type potential. It allows to allocate a typical frequency value to
each gravitat... | 0705.4143v2 |
2007-09-06 | Muon Identification without Iron | Muons can be identified with high efficiency and purity and reconstructed
with high precision is a detector with a dual readout calorimeter and a dual
solenoid to return the flux without iron. We shown CERN test beam data for the
calorimeter and calculations for the magnetic fields and the track
reconstruction. For iso... | 0709.0768v1 |
2007-11-28 | Evidence for Two Current Conduction in Iron | Measurements of resistivities of dilute iron based alloys show strong
deviations from Matthiessen's rule. These deviations can be explained by a
model in which spin up and spin down electrons conduct in parallel. The results
are consistent with the theory of impurity shielding in these alloys. [This
1967 paper provides... | 0711.4478v1 |
2008-04-03 | Orbital Degeneracy and the Microscopic Model of the FeAs Plane in the Iron-Based Superconductors | A microscopic model for the FeAs plane in the newly discovered Iron-based
superconductors is proposed with the emphasis on the role of the orbital
degeneracy between the Fe $3d_{xz}$ and $3d_{yz}$ orbital in the crystal field
environment. The model predicts commensurate antiferromagnetic ordered ground
state for the pa... | 0804.0536v1 |
2008-04-10 | Spin-triplet p-wave pairing in a 3-orbital model for iron pnictide superconductors | We examine the possibility that the superconductivity in the newly discovered
FeAs materials may be caused by the Coulomb interaction between d-electrons of
the iron atoms. We find that when the Hund's rule ferromagnetic interaction is
strong enough, the leading pairing instability is in spin-triplet p-wave
channel in ... | 0804.1739v3 |
2008-05-06 | The minimum model for the iron-based superconductors | A single band $t$-$U$-$J_1$-$J_2$ model is proposed as the minimum model to
describe the superconductivity of the newly discovered iron-based
superconductors $R(O_{1-x}F_x)FeAs$ and $RO_{1-x}FeAs$ ($R=La, Ce, Sm, Pr,
Nd,Gd$). With the mean-field approach, it is found that the pairing occurs in
the d-wave channel. In th... | 0805.0644v1 |
2008-05-07 | Design Methodology and Manufacture of a Microinductor | Potential core materials to supersede ferrite in the 0.5-10 MHz frequency
range are investigated. The performance of electrodeposited nickel-iron,
cobalt-iron-copper alloys and the commercial alloy Vitrovac 6025 have been
assessed through their inclusion within a custom-made solenoid microinductor.
Although the present... | 0805.0859v1 |
2008-06-10 | Synthesis and Microstructural Studies of Iron Based LaO1-xFxFeAs Superconducting Materials | We report on the synthesis and microstructural studies of fluorine based iron
doped superconductors. We have successfully synthesized the fluorine based new
superconducting material LaO1-xFxFeAs by choosing comparatively lower
temperature and longer synthesis duration. The superconducting transition
temperature that we... | 0806.1661v1 |
2008-06-17 | Large Seebeck coefficients in Iron-oxypnictides : a new route towards n-type thermoelectric materials | The iron-oxypnictide compounds, recently reported as a new class of
superconductors when appropriately doped, exhibit large Seebeck coefficients,
of the order of -100 microV/K, while keeping good electrical conductivity.
Their power factor shows a peak at low temperatures, suggesting possible
applications of these mate... | 0806.2751v1 |
2008-06-19 | Possible unconventional superconductivity in iron-based layered compound LaFePO: Study of heat capacity | Heat capacity measurements were performed on recently discovered iron based
layered superconductors, non doped LaFePO and fluorine doped LaFePO. A
relatively large electronic heat capacity coefficient and a small normalized
heat capacity jump at Tc = 3.3 K were observed in LaFePO. LaFePO0.94F0.06 had a
smaller electron... | 0806.3139v1 |
2008-06-30 | The superconductivity at 18 K in LiFeAs system | A new iron arsenide superconducting system LiFeAs was found that crystallizes
into a tetragonal structure with space group P4/nmm. The superconductivity with
Tc up to 18 K was observed in the compounds. This simple 111 type layered iron
arsenide superconductor can be viewed as an analogue of the infinite layer
structur... | 0806.4688v3 |
2008-07-04 | Lattice dynamical calculations of infinite layer iron oxides SrFeO2 and CaFeO2 | We report extensive lattice dynamical calculations of the newly discovered
infinite-layer iron oxides SrFeO2 and CaFeO2. For SrFeO2, the parameters of the
interatomic potential have been determined to reproduce the zone-centre phonon
frequencies reported using ab-initio calculations. Further we have extended the
potent... | 0807.0716v1 |
2008-07-28 | Multiple Gaps and Superfluid Density from Interband Pairing in Iron Oxypnictides | We study a four-band model for the iron oxypnictides, in which the
superconducting properties are assumed to be determined by the interband
coupling between hole-like and electron-like Fermi sheets. We show that
reasonable parameters can account for the angle-resolved photoemission spectra
showing multiple gaps in Ba$_... | 0807.4408v1 |
2008-08-09 | Transport and Magnetic Properties of FexVse2 (x = 0 - 0.33) | We present our results of the effect of Fe intercalation on the structural,
transport and magnetic properties of 1T-VSe2. Intercalation of iron, suppresses
the 110K charge density wave (CDW) transition of the 1T-VSe2. For the higher
concentration of iron, formation of a new kind of first order transition at
160K takes ... | 0808.1333v1 |
2008-08-24 | Theory for Superconductivity in Iron Pnictides at Large Coulomb U Limit | Superconductivity in iron pnictides is studied by using a two-orbital Hubbard
model in the large U limit. The Coulomb repulsion induces an orbital-dependent
pairing between charge carriers. The pairing is found mainly from the
scattering within the same Fermi pocket. The inter-pocket pair scatterings
determine the symm... | 0808.3234v2 |
2008-08-27 | Charge dynamics in the normal state of the iron oxypnictide superconductor LaFePO | We present the first infrared and optical study in the normal state of
ab-plane oriented single crystals of the iron-oxypnictide superconductor
LaFePO. We find that this material is a low carrier density metal with a
moderate level of correlations and exhibits signatures of electron-boson
coupling. The data is consiste... | 0808.3748v1 |
2008-09-04 | Impurity states in antiferromagnetic Iron Arsenides | We explore theoretically impurity states in the antiferromagnetic
spin-density wave state of the iron arsenide. Two types of impurity models are
employed: one has only the intraband scattering while the other has both the
intraband and interband scattering with the equal strength. Interestingly, the
impurity bound stat... | 0809.0795v1 |
2008-09-22 | High-Tc Superconductivity in some Heavy Rare-earth Iron-arsenide REFeAsO1-delta(RE = Ho, Y, Dy and Tb) Compounds | New iron-arsenide superconductors of REFeAsO1-delta (RE = Ho, Y, Dy and Tb)
were successfully synthesized by a high pressure synthesizing method with a
special rapid quenching process, with the onset superconducting critical
temperatures at 50.3 K, 46.5 K, 52.2K and 48.5 K for RE = Ho, Y, Dy and Tb
respectively. | 0809.3582v1 |
2008-10-13 | Antiferromagnetic Correlation and the Pairing Mechanism of the Cuprates and Iron Pnictides : a View From the Functional Renormalization Group Studies | We compare the one-loop functional renormalization group results for the
cuprates and the iron pnictides. Interestingly a coherent picture suggesting
that antiferromagnetic correlation causes pairing for both materials emerges. | 0810.2320v2 |
2008-10-17 | Structure, antiferromagnetism and superconductivity of the layered iron arsenide NaFeAs | A new layered iron arsenide NaFeAs isostructural with the superconducting
lithium analogue, displays evidence for the coexistence of superconductivity
and magnetic ordering. | 0810.3214v2 |
2008-10-28 | Enhanced low-energy spin dynamics with diffusive character in the iron-based superconductor (La0.87Ca0.13)FePO: Analogy with high Tc cuprates (A short note) | In a recent NMR investigation of the iron-based superconductor
(La0.87Ca0.13)FePO [Phys. Rev. Lett. 101, 077006 (2008)] Y. Nakai et al.
reported an anomalous behavior of the nuclear spin-lattice relaxation of 31P
nuclei in the superconducting state: The relaxation rate 1/T1 strongly depends
on the measurement frequency... | 0810.5135v1 |
2008-11-05 | Superconductivity in S-substituted FeTe | We have successfully synthesized a new superconducting phase of FeTe1-xSx
with a PbO-type structure. It has the simplest crystal structure in iron-based
superconductors. Superconducting transition temperature is about 10 K at x =
0.2. The upper critical field Hc2 was estimated to be ~70 T. The coherent
length was calcu... | 0811.0711v2 |
2008-12-01 | High - Temperature Superconductivity in Iron Based Layered Compounds | We present a review of basic experimental facts on the new class of high -
temperature superconductors - iron based layered compounds like REOFeAs
(RE=La,Ce,Nd,Pr,Sm...), AFe_2As_2 (A=Ba,Sr...), AFeAs (A=Li,...) and FeSe(Te).
We discuss electronic structure, including the role of correlations, spectrum
and role of coll... | 0812.0302v1 |
2008-12-31 | Experimental Detection of Sign-Reversal Pairing in Iron-Based Superconductors | We propose a modified Josephson corner-junction experiment which can test
whether the order parameter in the iron pnictides changes sign between the
electron and hole pockets of the Fermi surface. | 0901.0038v3 |
2009-01-19 | Possible Kondo effect in the iron arsenides | The normal state of the iron arsenides shows the poor metallic behavior mixed
with strong magnetic fluctuations. In particular, some FeAs-1111 and FeAs-122
compounds show the linear-T dependence of susceptibility above the spin-density
wave (SDW) transition and the logarithmic upturn of resistivity at low
temperatures.... | 0901.2787v2 |
2009-02-21 | Unconventional pairing originating from disconnected Fermi surfaces in the iron-based superconductor | For the iron-based high $T_c$ superconductor LaFeAsO$_{1-x}$F$_x$, we
construct a minimal model, where all of the five Fe $d$ bands turn out to be
involved. We then investigate the origin of superconductivity with a five-band
random-phase approximation by solving the Eliashberg equation. We conclude that
the spin fluct... | 0902.3691v1 |
2009-03-11 | Pairing in the iron arsenides: a functional RG treatment | We study the phase diagram of a microscopic model for the superconducting
iron arsenides by means of a functional renormalization group. Our treatment
establishes a connection between a strongly simplified two-patch model by
Chubukov et al. and a five-band- analysis by Wang et al.. For a wide parameter
range, the domin... | 0903.1963v1 |
2009-03-22 | Anomalous Magnetic Susceptibility in Iron Pnictides: Paramagnetic Phase | Observation of an anomalous temperature dependence of the spin
susceptibility, along with a spin gap in NMR, in the quantum paramagnetic
normal state of Iron Pnictides is a signature of an unusual metallic state. We
argue that both these anomalous features are associated with a wide
fluctuational regime dominated by dy... | 0903.3732v1 |
2009-03-24 | Band structure of new layered 17 K superconductor Sr4Sc2Fe2P2O6 in comparison with hypothetical Sr4Sc2Fe2As2O6 | The results of the ab initio FLAPW-GGA calculations of the band structure of
the newly synthesized tetragonal (space group P4/nmm) layered iron
phosphide-oxide: 17K superconductor Sr4Sc2Fe2P2O6 are presented. For
Sr4Sc2Fe2P2O6 the optimized structural data, the energy bands, total and
partial densities of states, Fermi... | 0903.4038v1 |
2009-04-01 | Electronic structure of Ti-doped Sr4Sc2Fe2As2O6 | First principle FLAPW-GGA calculations have been performed with the purpose
to understand the electronic properties for the newly synthesized tetragonal
(space group P4/nmm) layered iron arsenide-oxide: Sr4Sc2Fe2As2O6 doped with
titanium. The total and partial densities of states, low-temperature electron
specific heat... | 0904.0117v1 |
2009-04-07 | Evidence for polarons in iron pnictides of the Ln-1111 and AE-122 families | Examination of the electrical resistivities of iron pnictides shows that they
can be accounted by conduction by polarons. Their activation energies show a
linear behaviour with the critical temperatures of the spin density waves
(SDW), T*, as both vary with pressure. The slope matches the ratio SDW gap to
T*, while the... | 0904.1173v1 |
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