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2016-10-27
Influence of multiorbitals and anisotropic Coulomb interactions on isotope effect coefficient in doped Fe-based superconductors
The present work describes the theoretical analysis of isotope effect coefficient as a function of transition temperature in two orbital per site model Hamiltonian in iron based superconducting system. The expression of isotope effect coefficient has been computed numerically and self-consistently by employing Green's ...
1610.08888v1
2016-11-01
Missing Fe: hydrogenated iron nanoparticles
Although it was found that the FeH lines exist in the spectra of some stars, none of the spectral features in the ISM have been assigned to this molecule. We suggest that iron atoms interact with hydrogen and produce Fe-H nanoparticles which sometimes contain many H atoms. We calculate infrared spectra of hydrogenated ...
1611.00309v1
2016-11-25
Modeling the Anomalous Microwave Emission with Spinning Nanoparticles: No PAHs Required
In light of recent observational results indicating an apparent lack of correlation between the Anomalous Microwave Emission (AME) and mid-infrared emission from polycyclic aromatic hydrocarbons (PAHs), we assess whether rotational emission from spinning silicate and/or iron nanoparticles could account for the observed...
1611.08597v1
2017-01-18
Phase-separation control of K$_x$Fe$_{2-y}$Se$_2$ superconductor through rapid-quenching process
K$_x$Fe$_{2-y}$Se$_2$ exhibits an iron-vacancy ordering at $T_{\rm s} {\sim}270{\deg}$C and separates into two phases: a minor superconducting (iron-vacancy-disordered) phase and a major non-superconducting (iron-vacancy-ordered) phase. The microstructural and superconducting properties of this intermixture can be tune...
1701.04911v2
2017-05-19
The phonon softening due to melting of the ferromagnetic order in elemental iron
We study the fundamental question of the lattice dynamics of a metallic ferromagnet in the regime where the static long range magnetic order is replaced by the fluctuating local moments embedded in a metallic host. We use the \textit{ab initio} Density Functional Theory(DFT)+embedded Dynamical Mean-Field Theory(eDMFT) ...
1705.06877v2
2017-06-21
Emergent phases in iron pnictides: Double-Q antiferromagnetism, charge order and enhanced nematic correlations
Electron correlations produce a rich phase diagram in the iron pnictides. Earlier theoretical studies on the correlation effect demonstrated how quantum fluctuations weaken and concurrently suppress a $C_2$-symmetric single-Q antiferromagnetic order and a nematic order. Here we examine the emergent phases near the quan...
1706.07087v2
2017-09-26
Timing and Charge measurement of single gap Resistive Plate Chamber Detectors for INO-ICAL Experiment
The recently approved India-based Neutrino Observatory will use the world's largest magnet to study atmospheric muon neutrinos. The 50 kiloton Iron Calorimeter consists of iron alternating with single-gap resistive plate chambers. A uniform magnetic field of $\sim$1.5 T is produced in the iron using toroidal-shaped cop...
1709.08946v1
2018-01-03
Distinguishing black holes and naked singularities with iron line spectroscopy
It is commonly thought that the final product of gravitational collapse is a black hole. Nevertheless, theoretical studies have not yet provided a final answer to the question whether black holes are the only possible outcome or whether naked singularities are also allowed. Observational tests may thus represent a comp...
1801.00867v2
2018-01-24
Evidence for a neutral iron line generated by MeV protons from supernova remnants interacting with molecular clouds
Supernova remnants (SNRs) have been prime candidates for Galactic cosmic-ray accelerators. When low-energy cosmic-ray protons (LECRp) collide with interstellar gas, they ionize neutral iron atoms and emit the neutral iron line (Fe I K$\alpha$) at 6.40keV. We search for the iron K-shell line in seven SNRs from the Suzak...
1801.07881v1
2018-02-11
Two-dimensional Iron Monocarbide with Planar Hypercoordinate Iron and Carbon
We report on the theoretical discovery of Iron monocarbide binary sheets stabilized at two-dimensional confined space, which we call tetragonal-FeC (t-FeC) and orthorhombic-FeC (o-FeC), respectively. From the energy viewpoint, the proposed t-FeC is the global minimum configuration in the 2D space, and each carbon atom ...
1802.03673v1
2018-03-01
Strong electronic correlations and Fermi surface reconstruction in the quasi-one dimensional iron superconductor BaFe2S3
BaFe2S3 is a special iron superconductor with two-leg ladder structure which can help to unravel the role played by the electronic correlations in high-Tc superconductivity. At zero pressure it is insulating with stripe antiferromagnetic (AF) order and superconductivity emerges under pressure. We use a slave-spin techn...
1803.00282v1
2018-03-28
Iron line spectroscopy with Einstein-dilaton-Gauss-Bonnet black holes
Einstein-dilaton-Gauss-Bonnet gravity is a well-motivated alternative theory of gravity that emerges naturally from string theory. While black hole solutions have been known in this theory in numerical form for a while, an approximate analytical metric was obtained recently by some of us, which allows for faster and mo...
1803.10819v1
2018-04-13
Subsurface Cation Vacancy Stabilization of the Magnetite (001) Surface
Iron oxides play an increasingly prominent role in heterogeneous catalysis, hydrogen production, spintronics and drug delivery. The surface or material interface can be performance limiting in these applications, so it is vital to determine accurate atomic-scale structures for iron oxides and understand why they form. ...
1804.04836v1
2018-04-21
Iron line spectroscopy of black holes in asymptotically safe gravity
We study the iron line shape expected in the reflection spectrum of accretion disks around black holes in asymptotically safe gravity. We compare the results of our simulations with the iron line shapes expected in the reflection spectrum of accretion disks around Kerr black holes to see if the technique of iron line s...
1804.07955v2
2018-04-30
New iron-based multiferroics with improper ferroelectricity
In this contribution to the special issue on magnetoelectrics and their applications, we focus on some single phase multiferroics theoretically predicted and/or experimentally discovered by the authors in recent years. In these materials, iron is the common core element. However, these materials are conceptually differ...
1804.11125v1
2018-05-23
Single-crystal growth of iron-based superconductor La$_{0.34}$Na$_{0.66}$Fe$_2$As$_2$
We report single-crystal growth of La$_{0.34}$Na$_{0.66}$Fe$_2$As$_2$ iron-based superconductor with the size of several millimeters. The samples were accidentally obtained in trying to grow LaFeAsO$_{1-y}$F$_y$ ( $y \geq$ 0.8 ) single crystals with NaAs and NaF flux. The sample shows both antiferromagnetic and structu...
1805.08923v2
2018-06-16
Iron Line Spectroscopy of Black Holes in Vector-Tensor Galileons Modified Gravity
Recently, a rotating black hole solution was found in Vector-Tensor Galileons modified gravity that has some significant differences from the Kerr black hole solution. We study the iron line shape that is part of the reflection spectrum of accretion disks around black holes in this new black hole solution. We simulate ...
1806.06240v2
2018-08-07
Forming Mercury by Giant Impacts
The origin of Mercury's high iron-to-rock ratio is still unknown. In this work we investigate Mercury's formation via giant impacts and consider the possibilities of a single giant impact, a hit-and-run, and multiple collisions in one theoretical framework. We study the standard collision parameters (impact velocity, m...
1808.02448v1
2018-08-26
Realization of continuously electron doping in bulk iron selenides and identification of a new superconducting zone
It is known that iron selenide superconductors exhibit unique characteristics distinct from iron pnicitides, especially in the electron-doped region. However, acomprehensive study of continuous carrier doping ang the corresponding crystal structures of FeSe is still lacking, mainly due to the difficulties in controllin...
1808.08501v1
2018-09-13
Dendritic Oxide Growth in Zero-Valent Iron Nanofilms Revealed by Atom Probe Tomography
Atom probe tomography (APT) analysis of chemically pure nanofilms of zero-valent iron (Fe(0), or ZVI) and their thermal oxide nano-overlayers reveals the presence of dendritic iron oxide features that extend from the oxide nano-overlayer surface into the ZVI bulk. The dendrites are observed by APT to be in the 5 nm x 1...
1809.04909v2
2018-10-28
A mathematical and experimental study on iron rings formation in porous stones
In this interdisciplinary paper, we study the formation of iron precipitates - the so-called Liesegang rings - in Lecce stones in contact with iron source. These phenomena are responsible of exterior damages of lapideous artifacts, but also in the weakening of their structure. They originate in presence of water, deter...
1810.11825v1
2019-01-10
A topology optimized switchable permanent magnet system
The design of a magnetic field source that can switch from a high field to a low field configuration by rotation by $90^\circ$ of a set of iron pieces is investigated using topology optimization. A Halbach cylinder is considered as the magnetic field source and iron inserts are placed in the air gap of the Halbach cyli...
1901.03110v1
2019-01-10
Topological Vortex Phase Transitions in Iron-Based Superconductors
We study topological vortex phases in iron-based superconductors. Besides the previously known vortex end Majorana zero modes (MZMs) phase stemming from the existence of a three dimensional (3D) strong topological insulator state, we show that there is another topologically nontrivial phase as iron-based superconductor...
1901.03120v1
2019-01-28
Surface passivation by graphene in the lubrication of iron: A comparison with bronze
It has been recently reported that graphene is able to significantly reduce the friction coefficient of steel-on-steel sliding contacts. The microscopic origin of this behavior has been attributed to the mechanical action of load carrying capacity. However, a recent work highlighted the importance of the chemical actio...
1901.09616v1
2019-03-19
First performance test of 30 mm iron-based superconductor single pancake coil under 24 T background field
The iron-based superconductor (IBS) single pancake coil (SPC) with 30 mm inner diameter was firstly fabricated and tested under 24 T background field. This SPC was successfully made using the 7-filamentary Ba1-xKxFe2As2 (Ba122) tape by wind-and-react method. This IBS coil show the highest Ic value at magnetic field rep...
1903.07960v1
2019-03-29
Nematic and Antiferromagnetic Quantum Criticality in a Multi-Orbital Hubbard Model for Iron Pnictides
The extent to which quantum criticality drives the physics of iron pnictides is a central question in the field. Earlier theoretical considerations were based on an effective field theory, and the proposed realization in P-doped iron arsenides has received extensive experimental evidence. To connect the quantum critica...
1903.12625v1
2019-04-08
High-energy spin fluctuation in low-$T_{\rm c}$ iron-based superconductor LaFePO$_{0.9}$
Spin fluctuations are widely believed to play an important role in the superconducting mechanisms of unconventional high-temperature superconductors. Spin fluctuations have been observed in iron-based superconductors as well. However, in some iron-based superconductors such as LaFePO$_{0.9}$, they have not been observe...
1904.03854v1
2019-06-04
Pairing symmetry and topological surface state in iron-chalcogenide superconductors
The symmetries of superconducting gap functions remain an important question of iron-based superconductivity. Motivated by the recent angle-resolved photoemission spectroscopic measurements on iron-chalcogenide superconductors, we investigate the influence of pairing symmetries on the topological surface state. If the ...
1906.01754v3
2019-06-20
Effects of spin-orbit coupling on the neutron spin resonance in iron-based superconductors
The so-called neutron spin resonance consists of a prominent enhancement of the magnetic response at a particular energy and momentum transfer upon entering the superconducting state of unconventional superconductors. In the case of iron-based superconductors, the neutron resonance has been extensively studied experime...
1906.08566v1
2019-08-26
New thermodynamic constraints on internal, thermal and magnetic states of terrestrial-like Super-Earths
Ascertaining rocky exoplanets dynamic evolution requires better understanding of key internal thermophysical processes that shaped their geological surfaces, heat fluxes, volatiles and atmospheric content. New high-pressure experiments on iron and silicates compressible, melting and transport properties are providing n...
1908.09871v1
2019-11-03
Interpreting Verbal Irony: Linguistic Strategies and the Connection to the Type of Semantic Incongruity
Human communication often involves the use of verbal irony or sarcasm, where the speakers usually mean the opposite of what they say. To better understand how verbal irony is expressed by the speaker and interpreted by the hearer we conduct a crowdsourcing task: given an utterance expressing verbal irony, users are ask...
1911.00891v3
2020-03-27
Phonon dispersions throughout the iron spin crossover in ferropericlase
Ferropericlase (Fp), (Mg$_\mathrm{1-x}$Fe$_\mathrm{x}$)O, is the second most abundant phase in the Earths lower mantle. At relevant pressure-temperature conditions, iron in Fp undergoes a high spin (HS), S=2, to low spin (LS), S=0, state change. The nature of this phenomenon is quite well understood now, but there are ...
2003.12348v1
2020-06-11
Embracing defects and disorder in magnetic nanoparticles
Iron oxide nanoparticles have tremendous scientific and technological potential in a broad range of technologies, from energy applications to biomedicine. To improve their performance, single-crystalline and defect-free nanoparticles have thus far been aspired. However, in several recent studies defect-rich nanoparticl...
2006.06474v1
2020-11-20
An Investigation of Commercial Iron Oxide Nanoparticles: Advanced Structural and Magnetic Properties Characterization
Magnetic nanoparticles (MNPs) have been extensively used as tiny heating sources in magnetic hyperthermia therapy, contrast agents in magnetic resonance imaging (MRI), tracers in magnetic particle imaging (MPI), carriers for drug/gene delivery, etc. There have emerged many magnetic nanoparticle/microbeads suppliers sin...
2011.10215v1
2020-11-23
A Learning-based Optimization Algorithm:Image Registration Optimizer Network
Remote sensing image registration is valuable for image-based navigation system despite posing many challenges. As the search space of registration is usually non-convex, the optimization algorithm, which aims to search the best transformation parameters, is a challenging step. Conventional optimization algorithms can ...
2011.11365v1
2021-02-01
Confirmation of Asymmetric Iron Absorption in WASP-76b with HARPS
Hot Jupiters are predicted to have hot, clear daysides and cooler, cloudy nightsides. Recently, an asymmetric signature of iron absorption has been resolved in the transmission spectrum of WASP-76b using ESPRESSO on ESO's Very large Telescope. This feature is interpreted as being due to condensation of iron on the nigh...
2102.01095v1
2021-03-07
IRON: Invariant-based Highly Robust Point Cloud Registration
In this paper, we present IRON (Invariant-based global Robust estimation and OptimizatioN), a non-minimal and highly robust solution for point cloud registration with a great number of outliers among the correspondences. To realize this, we decouple the registration problem into the estimation of scale, rotation and tr...
2103.04357v2
2021-03-11
Flatband-Induced Itinerant Ferromagnetism in RbCo$_2$Se$_2$
$A$Co$_2$Se$_2$ ($A$=K,Rb,Cs) is a homologue of the iron-based superconductor, $A$Fe$_2$Se$_2$. From a comprehensive study of RbCo$_2$Se$_2$ via measurements of magnetization, transport, neutron diffraction, angle-resolved photoemission spectroscopy, and first-principle calculations, we identify a ferromagnetic order a...
2103.06528v1
2021-04-20
Bulk superconductivity in FeTe$_{1-x}$Se$_{x}$ via physicochemical pumping of excess iron
The iron-based superconductor FeTe$_{1-x}$Se$_{x}$ has attracted considerable attention as a candidate topological superconductor owing to a unique combination of topological surface states and bulk high-temperature superconductivity. The superconducting properties of as-grown single crystals, however, are highly varia...
2104.10145v1
2021-05-26
Prenatal stress perturbs fetal iron homeostasis in a sex-specific manner
What is the influence of chronic maternal prenatal stress (PS) on fetal iron homeostasis? In a prospective case-control study in 164 pregnant women, we show that cord blood transferrin saturation is lower in male stressed neonates. The total effect of PS exposure on fetal ferritin revealed a decrease of 15.4% compared ...
2105.12809v3
2021-06-02
Effective exchange interaction for terahertz spin waves in iron layers
The exchange stiffness is a central material parameter of all ferromagnetic materials. Its value controls the Curie temperature as well as the dynamic properties of spin waves to a large extend. Using ultrashort spin current pulses we excite perpendicular standing spin waves (PSSW) in ultrathin epitaxial iron layers at...
2106.01066v1
2021-06-08
Topological Superconductivity in an s-wave Superconductor and Its Implication to Iron-based Superconductors
In the presence of both space and time reversal symmetries, an s-wave A1g superconducting state is usually topologically trivial. Here we demonstrate that an exception can take place in a type of nonsymmorphic lattice structures. We specify the demonstration in a system with a centrosymmetric space group P4/nmm, the sy...
2106.04200v1
2021-08-10
Metallic nature and site-selective magnetic collapse in iron oxide Fe4O5 at the extreme conditions of Earth's deep interior
Properties of iron oxides at the extreme conditions are of essential importance in condensed matter physics and Geophysics. The recent discovery of a new type of iron oxide, Fe4O5, at high pressure and high temperature of Earth's deep interior attracts great interests. In this paper, we report the electronic structure ...
2108.04477v1
2021-11-30
Early differentiation of magmatic iron meteorite parent bodies from Mn-Cr chronometry
Magmatic iron meteorite groups such as IIAB, IIIAB and IVA, represent the largest sampling of extraterrestrial core material from the earliest accreted distinct planetary bodies in the solar system. Chromium isotope compositions of chromite/daubreelite from seven samples, translated into 53Cr/52Cr model ages, provide r...
2111.15291v1
2022-08-18
Role of strain on the stability of B, C, N, and O in Iron
The preference for the occupation of solute atoms like B, C, N, and O at various sites in iron is generally explained by the size of the solute and the volume available for the solute atoms to occupy. Such an explanation based on the size of solute atoms and available space at the occupation site assumes that distortio...
2208.08680v1
2022-11-09
Quantitative Susceptibility Mapping in Cognitive Decline: A Review of Technical Aspects and Applications
In the human brain, essential iron molecules for proper neurological functioning exist in transferrin (tf) and ferritin (Fe3) forms. However, its unusual increment manifests iron overload, which reacts with hydrogen peroxide. This reaction will generate hydroxyl radicals, and irons higher oxidation states. Further, thi...
2211.04764v1
2022-11-15
The Dissipation of the Solar Nebula Constrained by Impacts and Core Cooling in Planetesimals
Rapid cooling of planetesimal cores has been inferred for several iron meteorite parent bodies based on metallographic cooling rates, and linked to the loss of their insulating mantles during impacts. However, the timing of these disruptive events is poorly constrained. Here, we used the short-lived 107Pd / 107Ag decay...
2211.08306v1
2023-01-02
Enhance the Field Strength by Adding Soft Iron in the Hybrid Permanent magnet
Permanent magnet has a small and compact structure, is especially suitable for a narrow space. With the aid of soft iron, the magnetic field can be increased much more and the field uniformity can be well controlled. Most Permanent magnets have a symmetry structure; the soft iron can be selected as the float magnet pol...
2301.00532v1
2023-05-22
Ion-selective scattering studied by the variable-energy electron irradiation of Ba$_{0.2}$K$_{0.8}$Fe$_2$As$_2$ superconductor
Low-temperature variable-energy electron irradiation was used to induce non-magnetic disorder in a single crystal of hole-doped iron-based superconductor, Ba$_{1-x}$K$_x$Fe$_2$As$_2$, $x=$0.80. To avoid systematic errors, the beam energy was adjusted non-consequently for five values between 1.0 and 2.5 MeV, whence samp...
2305.13217v1
2024-01-16
Detection of the neutral iron line from the supernova remnant W49B with Suzaku
Recent studies of supernova remnants (SNRs) have revealed that some SNRs exhibit a neutral iron line emission at 6.4 keV. This line has been proposed to originate from the interaction of high-energy particles formed in the SNR shell with the surrounding cold matter. We searched for the neutral iron line emission in the...
2401.08234v1
1999-07-26
First Constraints on Iron Abundance versus Reflection Fraction from the Seyfert~1 Galaxy MCG--6-30-15
We report on a joint ASCA and RXTE observation spanning an $\sim$ 400~ks time interval of the bright Seyfert~1 galaxy MCG--6-30-15. The data clearly confirm the presence of a broad skewed iron line ($W_{K\alpha} \sim$ 266 eV) and Compton reflection continuum at higher energies reported in our previous paper. We also in...
9907352v1
1999-12-01
On the lack of X-ray iron line reverberation in MCG-6-30-15: Implications for the black hole mass and accretion disk structure
We use the method of Press, Rybicki & Hewitt (1992) to search for time lags and time leads between different energy bands of the RXTE data for MCG-6-30-15. We tailor our search in order to probe any reverberation signatures of the fluorescent iron Kalpha line that is thought to arise from the inner regions of the black...
9912001v1
2003-10-29
The XMM-Newton Iron Line Profile of NGC 3783
We report on observations of the iron K line in the nearby Seyfert 1 galaxy, NGC 3783, obtained in a long, 2 orbit (240 ks) XMM-Newton observation. The line profile obtained exhibits two strong narrow peaks at 6.4 keV and at 7.0 keV, with measured line equivalent widths of 120 and 35 eV respectively. The 6.4 keV emissi...
0310820v1
2006-09-25
Tracing the evolution in the iron content of the ICM
We present a Chandra analysis of the X-ray spectra of 56 clusters of galaxies at z>0.3, which cover a temperature range 3<kT<15 keV. Our analysis is aimed at measuring the iron abundance in the intra-cluster medium (ICM) out to the highest redshift probed to date. We made use of combined spectral analysis performed ove...
0609664v3
2006-10-31
Tracing the evolution in the iron content of the ICM
We present a Chandra analysis of the X-ray spectra of 56 clusters of galaxies at z>0.3, which cover a temperature range of 3>kT>15 keV. Our analysis is aimed at measuring the iron abundance in the ICM out to the highest redshift probed to date. We find that the emission-weighted iron abundance measured within (0.15-0.3...
0610940v1
2007-03-12
Evolution in the iron abundance of the ICM
We present a Chandra analysis of the X-ray spectra of 56 clusters of galaxies at $z>0.3$, which cover a temperature range of $3> kT > 15$ keV. Our analysis is aimed at measuring the iron abundance in the ICM out to the highest redshift probed to date. We find that the emission-weighted iron abundance measured within $(...
0703261v1
2009-06-17
Fabrication and characterization of iron pnictide wires and bulk materials through the powder-in-tube method
The recent discovery of superconductivity in the iron based superconductors with very high upper critical fields presents a new possibility for practical applications, but fabricating fine-wire is a challenge because of mechanically hard and brittle powders and the toxicity and volatility of arsenic. In this paper, we ...
0906.3114v1
2012-04-20
The Carina Project. V. The impact of NLTE effects on the iron content
We have performed accurate iron abundance measurements for 44 red giants (RGs) in the Carina dwarf spheroidal (dSph) galaxy. We used archival, high-resolution spectra (R~38,000) collected with UVES at ESO/VLT either in slit mode (5) or in fiber mode (39, FLAMES/GIRAFFE-UVES). The sample is more than a factor of four la...
1204.4612v2
2014-08-15
Protected Fe valence in quasi-two dimensional $α$-FeSi$_2$
We report the first comprehensive study of the high temperature form ($\alpha$-phase) of iron disilicide. Measurements of the magnetic susceptibility, magnetization, heat capacity and resistivity were performed on well characterized single crystals. With a nominal iron $d^6$ configuration, and a quasi-two dimensional c...
1408.3606v2
2016-07-04
Origin of the Characteristic X-ray Spectral Variations of IRAS 13224$-$3809
The Narrow-line Seyfert 1 galaxy (NLS1) IRAS 13224$-$3809 is known to exhibit significant X-ray spectral variation, a sharp spectral drop at $\sim$ 7 keV, strong soft excess emission, and a hint of iron L-edge feature, which is very similar to the NLS1 1H 0707$-$495. We have proposed the "Variable Double Partial Coveri...
1607.00879v1
2017-08-05
Nematic Fluctuations in Iron-Oxychalcogenide Mott Insulators
Nematic fluctuations occur in a wide range of physical systems from liquid crystals to biological molecules to solids such as exotic magnets, cuprates and iron-based high-$T_c$ superconductors. Nematic fluctuations are thought to be closely linked to the formation of Cooper-pairs in iron-based superconductors. It is un...
1708.01693v4
2020-01-22
Superconductivity by Hidden Spin Fluctuations in Electron-Doped Iron Selenide
Berg, Metlitski and Sachdev, Science 338, 1606 (2012), have shown that the exchange of hidden spin fluctuations by conduction electrons with two orbitals can result in high-temperature superconductivity in copper-oxide materials. We introduce a similar model for high-temperature iron-selenide superconductors that are e...
2001.07908v3
2020-04-25
Reconciliation of experiments and theory on transport properties of iron and the geodynamo
The amount of heat transport from the core, which constrains the dynamics and thermal evolution of the region, depends on the transport properties of iron. Ohta et al.(2016) and Konopkova et al.(2016) measured electrical resistivity and thermal conductivity of iron, respectively, in laser-heated diamond anvil cells (DA...
2004.12035v1
2020-09-29
The iron record of asteroidal processes in carbonaceous chondrites
The valence of iron has been used in terrestrial studies to trace the hydrolysis of primary silicate rocks. Here, we use a similar approach to characterize the secondary processes, namely thermal metamorphism and aqueous alteration, that have affected carbonaceous chondrites. X-ray absorption near-edge structure spectr...
2009.13950v2
2020-09-30
DEEPMIR: A DEEP neural network for differential detection of cerebral Microbleeds and IRon deposits in MRI
Lobar cerebral microbleeds (CMBs) and localized non-hemorrhage iron deposits in the basal ganglia have been associated with brain aging, vascular disease and neurodegenerative disorders. Particularly, CMBs are small lesions and require multiple neuroimaging modalities for accurate detection. Quantitative susceptibility...
2010.00148v3
2022-01-31
Green steel at its crossroads: hybrid hydrogen-based reduction of iron ores
Iron- and steelmaking cause ~7% of the global CO2 emissions, due to the use of carbon for the reduction of iron ores. Replacing carbon by hydrogen as the reductant offers a pathway to reduce emissions. However, production of hydrogen using renewable energy will remain a bottlenecks, because making the annual crude stee...
2201.13356v1
2022-03-09
Accounting for iron-related off-target binding effects of 18F-AV1451 PET in the evaluation of cognition and microstructure in APOE-e4+ MCI
The pathology of Alzheimer's disease (AD) and mild cognitive impairment (MCI) is characterized by the presence of beta-amyloid extracellular plaques and neurofibrillary tangles containing hyper-phosphorylated tau. Individuals carrying the apolipoprotein E-e4 (APOE-e4) allele are at increased risk of cognitive decline a...
2203.16444v1
2022-12-13
On the surface chemisorption of oxidizing fine iron particles: insights gained from molecular dynamics simulations
Molecular dynamics (MD) simulations are performed to investigate the thermal and mass accommodation coefficients (TAC and MAC, respectively) for the combination of iron(-oxide) and air. The obtained values of TAC and MAC are then used in a point-particle Knudsen model to investigate the effect of chemisorption and the ...
2212.06432v2
1995-06-20
On the Bilayer Coupling in the Yttrium-Barium Family of High Temperature Superconductors
We present and solve a model for the susceptibility of two CuO2 planes coupled by an interplane coupling J_perp and use the results to analyze a recent "cross-relaxation" NMR experiment on Y2Ba4Cu7O15. We deduce that in this material the product of J_perp and the maximum value of the in-plane susceptibility chi_max var...
9506088v1
1996-06-04
On the Bilayer Coupling in the Yttrium-Barium Family of High Temperature Superconductors
We derive the expressions needed to interpret experiments relating to interplane magnetic coupling in YBa$_{2}$Cu$_{3}$O$_{6+x}$ and related materials, and use the results to interpret measurements of the optical magnon energy in YBa_{2}Cu_{3}O_{6.2} and of the NMR ``cross-relaxation" rate in Y_2Ba_{4}Cu_{7}O_{15}. We ...
9606008v2
1997-01-29
Local structure studies of the underdoped-overdoped transition in YBa_2Cu_3O_x. Measurement of the yttrium y-ray absorption fine structure
We have measured the extended x-ray absorption-fine-structure (EXAFS) at the Y-K edge of YBa_2Cu_3O_x for x=6.801, 6.947, 6.968, 6.984 at T=20-300 K. Across the underdoped-overdoped transition the Y-Cu2 pairs exhibit harmonic vibrations which freeze out in the superconducting phase, whereas the Y-O2,3 pairs exhibit str...
9701208v1
2000-10-06
Magnetic relaxation phenomena and cluster glass properties of La{0.7-x}Y{x}Ca{0.3}MnO{3} manganites
The dynamic magnetic properties of the distorted perovskite system La{0.7-x}Y{x}Ca{0.3}MnO{3} (0 <= x <= 0.15) have been investigated by ac-susceptibility and dc magnetization measurements, with emphasis on relaxation and aging studies. They evidence for x >= 0.10 the appearance of a metallic cluster glass phase, that ...
0010110v2
2001-04-22
Nonadiabatiic superconductivity in MgB2 and cuprates
The Fermi energy, Ef of newly discovered high-Tc superconductor MgB2 and cuprates is estimated from the measured London penetration depth using a parameter-free expression. Ef of MgB2 and more than 30 lanthanum, yttrium and mercury-based cuprates appears to be about or below 100 meV, depending on doping. There is every...
0104413v1
2001-05-07
Possibility of the investigation of the X-ray diffraction patterns for yttrium ceramic YBa2Cu3Ox having different oxygen stoichiometry on the basis of the mixed-layer crystal model
In view of the strong anisotropy of oxygen diffusion in high-Tc ceramic YBa2Cu3Ox, it is supposed that a polycrystalline sample of this material can be presented as consisting of crystal grains where each grain was formed by a certain sequence of layers with tetragonal or orthorhombic phase structure. The theory of sca...
0105133v1
2002-09-12
Electron momentum density in yttrium
A simultaneous analysis of high-resolution directional Compton profiles and two-dimensional angular correlation of positron annihilation experimental data has been performed by studying both a directional anisotropy of measured spectra and reconstructed densities. The results were compared with theoretical fully-relati...
0209297v1
2003-06-23
Disorder effects at low temperatures in La_{0.7-x}Y_{x}Ca_{0.3}MnO_{3} manganites
With the aim of probing the effect of magnetic disorder in the low-temperature excitations of manganites, specific-heat measurements were performed in zero field, and in magnetic fields up to 9 T in polycrystalline samples of La_{0.7-x}Y_{x}Ca_{0.3}MnO_{3}, with Y concentrations x=0, 0.10, and 0.15. Yttrium doping yiel...
0306582v1
2004-10-01
Magnetic Properties of Cuprate Perovskites
The magnetic susceptibility of underdoped yttrium and lanthanum cuprates is interpreted based on the self-consistent solution of the t-J model of a Cu-O plane. The calculations reproduce correctly the frequency dependencies of the susceptibility in YBa2Cu3O_{7-y} and La_{2-x}Sr_xCuO4 attributing their dissimilarity to ...
0410009v1
2005-02-18
Accuracy of ab initio methods in predicting the crystal structures of metals: review of 80 binary alloys
Predicting and characterizing the crystal structure of materials is a key problem in materials research and development. We report the results of ab initio LDA/GGA computations for the following systems: AgAu, AgCd, AgMg, AgMo*, AgNa, AgNb*, AgPd, AgRh*, AgRu*, AgTc*, AgTi, AgY, AgZr, AlSc, AuCd, AuMo*, AuNb, AuPd, AuP...
0502465v1
2005-08-27
The thermodynamic stability and hydration enthalpy of strontium cerate doped by yttrium
The standard molar enthalpy of formation of SrY0.05Ce0.95O2.975 has been derived by combining the enthalpy of solution of this compound in 1 M HCl + 0.1 KI obtained by us and auxiliary literature data. The following value has been derived: DfH (SrY0.05Ce0.95O2.975, s, 298.15 K) = -1720.4 (3.4) kJ/mol. The obtained valu...
0508654v1
2005-10-21
Superconductivity mediated by a soft phonon mode: specific heat, resistivity, thermal expansion and magnetization of YB6
The superconductor YB6 has the second highest critical temperature Tc among the boride family MBn. We report measurements of the specific heat, resistivity, magnetic susceptibility and thermal expansion from 2 to 300 K, using a single crystal with Tc = 7.2 K. The superconducting gap is characteristic of medium-strong c...
0510572v3
2006-07-07
Polymer-Nanoparticle Complexes : from Dilute Solution to Solid State
We report on the formation and the structural properties of supermicellar aggregates also called electrostatic complexes, made from mineral nanoparticles and polyelectrolyte-neutral block copolymers in aqueous solutions. The mineral particles put under scrutiny are ultra-fine and positively charged yttrium hydroxyaceta...
0607182v1
2006-12-01
Two types of Hc2(T) dependences in Bi_2Sr_2Ca_(1-x)Y_xCu_2O_(8+delta) with different Yttrium content
We reanalyze the magnetization data collected on Bi_2Sr_2Ca_(1-x)Y_xCu_2O_(8+y) samples (Kim at al, Phys. Rev. B 72, 64525 (2005)) and argue that the method, which was used for the analysis of equilibrium magnetization data, is not adequate to the experimental situation. As a result, the temperature dependencies of the...
0612031v1
2007-03-20
Steric quenching of the switchable mirror effect Phys. Rev. B 75, 104109 (2007)
Scandium was substituted for yttrium to observe the effect of unit cell size on the optical metal-to-insulator (MIT) transition in the Y_(1-z)Sc_(z)H_(x) alloy system. The optical transmittance decreases significantly for z>0.10. Simultaneous electrical resistivity measurements confirm the transition from trihydride to...
0703521v1
2003-04-07
Search for quantum transducers between electromagnetic and gravitational radiation: A measurement of an upper limit on the transducer conversion efficiency of yttrium barium copper oxide
A minimal coupling rule for the coupling of the electron spin to curved spacetime in general relativity suggests the possibility of a coupling between electromagnetic and gravitational radiation mediated by means of a quantum fluid. Thus quantum transducers between these two kinds of radiation fields might exist. We re...
0304026v1
2007-07-24
Terahertz spectroscopy of electromagnons in Eu_{1-x}Y_xMnO_3
Dielectric permittivity spectra of yttrium-doped EuMnO$_3$ in the composition range 0 =< x =< 0.5 have been investigated in the terahertz frequency range. Magnetoelectric contributions to the permittivity were observed in all compositions for ac electric fields parallel to the crystallographic a-axis. Well defined elec...
0707.3614v1
2007-11-10
Ab initio calculations of the electronic structure of cuprates using large scale cluster techniques
The local electronic structures of La2CuO4, three members of the Yttrium-family (YBa2Cu3O6, YBa2Cu3O7, and YBa2Cu4O8), and to some extent of Nd2CuO4 have been determined using all-electron ab-initio cluster calculations for clusters comprising up to thirteen planar copper atoms associated with their nearest planar and ...
0711.1606v1
2009-01-16
Surface superconducting states in yttrium hexaboride single crystal in a tilted magnetic field
We present the results of an experimental study of the nucleation of superconductivity at the surface of a single crystal YB$_6$ in a tilted dc magnetic field. A recently developed experimental technique allowed us to determine $H_{c3}$ at each side of the sample as a function of the angle between the dc magnetic field...
0901.2544v2
2009-12-23
The effect of anomalous adsorption of H2O and CO2 by pre-hydrated YBa_2Cu_3O_{6.53}
The results of a comprehensive study on the YBa_2Cu_3O_{6.53} oxide subjected to "mild" hydration (exposure at small values of pH2O) by a special technique have been reported. The material modified in this way acquires an interesting property; namely, in natural conditions it intensively absorbs large quantities of com...
0912.4601v1
2011-03-23
Numerical Simulation of Magnetic Interactions in Polycrystalline YFeO3
The magnetic behavior of polycrystalline yttrium orthoferrite was studied from the experimental and theoretical points of view. Magnetization measurements up to 170 kOe were carried out on a single-phase YFeO3 sample synthesized from heterobimetallic alkoxides. The complex interplay between weak-ferromagnetic and antif...
1103.4462v1
2011-04-07
Electrostatic Control of the Evolution from Superconductor to Insulator in Ultrathin Films of Yttrium Barium Copper Oxide
The electrical transport properties of ultrathin YBCO films have been modified using an electric double layer transistor configuration employing an ionic liquid. The films were grown on SrTiO3 substrates using high pressure oxygen sputtering. A clear evolution from superconductor to insulator was observed in nominally ...
1104.1357v1
2011-08-22
Adler-Bell-Jackiw anomaly in Weyl semi-metals: Application to Pyrochlore Iridates
Weyl semimetals are three dimensional analogs of graphene where the energy of the excitations are a linear function of their momentum. Pyrochlore Iridates $(A_{2}Ir_{2}O_{7})$ with A =yttrium or lanthanide element) are conjectured to be examples of such a system, with the low energy physics described by twenty four Wey...
1108.4426v2
2012-01-19
Quantum storage of polarization qubits in birefringent and anisotropically absorbing materials
Storage of quantum information encoded into true single photons is an essential constituent of long-distance quantum communication based on quantum repeaters and of optical quantum information processing. The storage of photonic polarization qubits is, however, complicated by the fact that many materials are birefringe...
1201.4097v3
2012-04-16
Nonlinear Induction Detection of Electron Spin Resonance
We present a new approach to the induction detection of electron spin resonance (ESR) signals exploiting the nonlinear properties of a superconducting resonator. Our experiments employ a yttrium barium copper oxide (YBCO) superconducting stripline microwave (MW) resonator integrated with a microbridge. A strong nonline...
1204.3588v2
2012-06-27
Effect of lattice volume and strain on the conductivity of BaCeY-oxide ceramic proton conductors
In-situ electrochemical impedance spectroscopy was used to study the effect of lattice volume and strain on the proton conductivity of the yttrium-doped barium cerate proton conductor by applying the hydrostatic pressure up to 1.25 GPa. An increase from 0.62 eV to 0.73 eV in the activation energy of the bulk conductivi...
1206.6287v1
2012-09-18
Magneto-optical trapping of diatomic molecules
The development of the magneto-optical trap revolutionized the fields of atomic and quantum physics by providing a simple method for the rapid production of ultracold, trapped atoms. A similar technique for producing a diverse set of dense, ultracold diatomic molecular species will likewise transform the study of stron...
1209.4069v1
2013-03-06
Crystal field with Wannier functions: Application to rare-earth aluminates
A method to calculate the crystal field parameters {\it ab initio} is proposed and applied to trivalent rare earth impurities in yttrium aluminate and to Tb$^{3+}$ ion in TbAlO$_3$. To determine crystal field parameters local Hamiltonian expressed in basis of Wannier functions is expanded in a series of spherical tenso...
1303.1281v3
2013-03-29
Point-contact spectroscopy of the phononic mechanism of superconductivity in YB6
Lortz et al. [Phys. Rev. B 73, 024512 (2006)] have utilized specific heat and resistivity measurements as "thermal spectroscopies" to deconvolve the spectrum of the electron-phonon interaction in YB$_6$ assuming a major role of the low frequency phonon mode in mediating superconductivity. Here, we present direct point-...
1303.7321v1
2013-07-23
Solution calorimetry investigations of new phase BaCe0.6Y0.3In0.1O2.8
The preparation of BaCeO3 doped by yttrium and indium oxides (BaCe0.6Y0.3In0.1O2.8) has been performed by solid-state reaction from BaCO3, CeO2, Y2O3, In2O3. The compound BaCe0.6Y0.3In0.1O2.8 has been synthesized for the first time. The X-ray measurements have showed that BaCe0.6Y0.3In0.1O2.8 has an orthorhombic struct...
1307.5940v1
2013-08-27
Nuclear beta decay with Lorentz violation
We consider the possibility of Lorentz-invariance violation in weak-decay processes. We present a general approach that entails modifying the W-boson propagator by adding a Lorentz-violating tensor to it. We describe the effects of Lorentz violation on nuclear beta decay in this scenario. In particular we show the expr...
1308.5829v2
2013-09-16
Results on damage induced by high-energy protons in LYSO calorimeter crystals
Lutetium-Yttrium Orthosilicate doped with Cerium (LYSO:Ce), as a bright scintillating crystal, is a candidate for calorimetry applications in strong ionizing-radiation fields and large high-energy hadron fluences as are expected at the CERN Large Hadron Collider after the planned High-Luminosity upgrade. There, proton-...
1309.3872v2