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2020-09-28
Intrusion of MeV-TeV Cosmic-Rays into Molecular Clouds Studied by Ionization, the Neutral Iron Line, and Gamma-Rays
Low-energy (~MeV) cosmic rays (CRs) ionize molecular clouds and create the neutral iron line (Fe I K\alpha) at 6.4 keV. On the other hand, high-energy (>~ GeV) CRs interact with the dense cloud gas and produce gamma rays. Based on a one-dimensional model, we study the spatial correlation among ionization rates of gas, ...
2009.13524v3
2020-10-02
Singular magnetic anisotropy in the nematic phase of FeSe
FeSe is arguably the simplest, yet the most enigmatic, iron-based superconductor. Its nematic but non-magnetic ground state is unprecedented in this class of materials and stands out as a current puzzle. Here, our NMR measurements in the nematic state of mechanically detwinned FeSe reveal that both the Knight shift and...
2010.01020v1
2020-10-05
Magnetic Iron Nanocubes Effectively Capture Epithelial and Mesenchymal Cancer Cells
Current methods for capturing circulating tumor cells (CTCs) are based on the overexpression of cytokeratin (CK) or epithelial cell-adhesion molecule (EpCAM) on cancer cells. However, during the process of metastasis, tumor cells undergo epithelial to mesenchymal transition (EMT) that can lead to the loss of CK/EpCAM e...
2010.02129v1
2020-10-14
An extremely metal-deficient globular cluster in the Andromeda Galaxy
Globular clusters (GCs) are dense, gravitationally bound systems of thousands to millions of stars. They are preferentially associated with the oldest components of galaxies, and measurements of their composition can therefore provide insight into the build-up of the chemical elements in galaxies in the early Universe....
2010.07395v1
2020-11-20
Photoionization Models for High Density Gas
Relativistically broadened and redshifted 6.4 -- 6.9 keV iron K lines are observed from many accretion powered objects, including X-ray binaries and active galactic nuclei (AGN). Existence of gas close to the central engine implies large radiation intensities and correspondingly large gas densities if the gas is to rem...
2011.10603v2
2020-12-18
Observation of d-wave Pomeranchuk nematic order in floating monolayer FeSe on FeSe/STO
As a foundation of condensed matter physics, the normal states of most metals are successfully described by Landau Fermi liquid theory with quasi-particles and their Fermi surfaces (FSs). The FSs sometimes become deformed or gapped at low temperatures owing to quasi-particle interactions, known as FS instabilities. A n...
2012.10136v1
2020-12-19
Majorana bound states in vortex lattices on iron-based superconductors
Majorana quasi-particles may arise as zero-energy bound states in vortices on the surface of a topological insulator that is proximitized by a conventional superconductor. Such a system finds its natural realization in the iron-based superconductor FeTe$_{0.55}$Se$_{0.45}$ that combines bulk $s$-wave pairing with spin ...
2012.10588v2
2020-12-29
Supernova neutrino detection through neutron emission by nuclei
Neutrinos from core collapse supernovae can excite nuclei of some detector materials beyond their neutron emission thresholds. Detection of these neutrons can give valuable information about the supernova explosion mechanism and possibly also throw light on neutrino properties. In this article, we give a brief review o...
2012.14888v1
2021-01-07
An injectable, self-healing and MMP-inhibiting hyaluronic acid gel via iron coordination
Regulating the activity of matrix metalloproteinases (MMPs) is a potential strategy for osteoarthritis (OA) therapy, although delivering this effect in a spatially and temporally localised fashion remains a challenge. Here, we report an injectable and self-healing hydrogel enabling factor-free MMP regulation and biomec...
2101.02414v1
2021-01-26
Superconductivity at 40 K in lithiation-processed [(Fe,Al)(OH)2][FeSe]1.2 with a layered structure
Exploration of new superconductors has always been one of the research directions in condensed matter physics. We report here a new layered heterostructure of [(Fe,Al)(OH)2][FeSe]1.2, which is synthesized by the hydrothermal ion-exchange technique. The structure is suggested by a combination of X-ray powder diffraction...
2101.10641v1
2021-04-08
The EOS/Resolution Conspiracy: Convergence in Proto-Planetary Collision Simulations
We investigate how the choice of equation of state (EOS) and resolution conspire to affect the outcomes of giant impact (GI) simulations. We focus on the simple case of equal mass collisions of two Earth-like $0.5\,M_\oplus$ proto-planets showing that the choice of EOS has a profound impact on the outcome of such colli...
2104.03559v2
2021-04-22
Chemical composition of stars with massive planets
Stellar parameters of 25 planet-hosting stars and abundances of Li, C, O, Na, Mg, Al, S, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Ni, Zn, Y, Zr, Ba, Ce, Pr, Nd, Sm and Eu, were studied based on homogeneous high resolution spectra and uniform techniques. The iron abundance [Fe/H] and key elements (Li, C, O, Mg, Si) indicative of ...
2104.10894v1
2021-05-02
High-energy magnetic excitations from heavy quasiparticles in CeCu$_2$Si$_2$
Magnetic fluctuations is the leading candidate for pairing in cuprate, iron-based and heavy fermion superconductors. This view is challenged by the recent discovery of nodeless superconductivity in CeCu$_2$Si$_2$, and calls for a detailed understanding of the corresponding magnetic fluctuations. Here, we mapped out the...
2105.00387v1
2021-05-19
An examination of local strain fields evolution in ductile cast iron through micromechanical simulations based on 3D imaging
Microscopic digital volume correlation (DVC) and finite element precoalescence strain evaluations are compared for two nodular cast iron specimens. Displacement fields from \textit{in-situ} 3D synchrotron laminography images are obtained by DVC. Subsequently the microstructure is explicitely meshed from the images cons...
2105.09859v3
2021-05-24
The Surface of (16) Psyche from Thermal Emission and Polarization Mapping
The asteroid (16) Psyche is the largest of the M-type asteroids, which have been hypothesized to be the cores of disrupted planetesimals and the parent bodies of the iron meteorites. While recent evidence has collected against a pure metal composition for Psyche, its spectrum and radar properties remain anomalous. We o...
2105.11372v1
2021-08-03
Spectroscopy and structural investigation of iron phosphorus trisulfide -- FePS$_3$
Lamellar structures of transition metal phosphorus trisulfides possess strong intralayer bonding, albeit adjacent layers are held by weak van der Waals interactions. Those compounds received enormous interest due to their unique combination of optical and long-range magnetic properties. Among them, iron phosphorus tris...
2108.01742v3
2021-08-08
V488 Per revisited: no strong mid-infrared emission features and no evidence for stellar/sub-stellar companions
We present characterization of the planetary system architecture for V488 Per, the dustiest main sequence star known with a fractional infrared luminosity of ~16%. Far-infrared imaging photometry confirms the existence of an outer planetary system dust population with blackbody-fit temperature of ~130 K. Mid-infrared s...
2108.03700v1
2021-08-20
Orbital-dependent modulation of the superconducting gap in uniaxially strained Ba$_{0.6}$K$_{0.4}$Fe$_2$As$_2$
Pairing symmetry which characterizes the superconducting pairing mechanism is normally determined by measuring the superconducting gap structure ($|\Delta_k|$). Here, we report the measurement of a strain-induced gap modulation ($\partial|\Delta_k|$) in uniaxially strained Ba$_{0.6}$K$_{0.4}$Fe$_2$As$_2$ utilizing angl...
2108.08986v1
2021-08-25
Synthesis of a High-Capacity α-Fe2O3@C Conversion Anode and a High-Voltage LiNi0.5Mn1.5O4 Spinel Cathode and Their Combination in a Li-Ion Battery
A Li-conversion alpha-Fe2O3@C nanocomposite anode and a high-voltage LiNi0.5Mn1.5O4 cathode are synthesized in parallel, characterized, and combined in a Li-ion battery. alpha-Fe2O3@C is prepared via annealing of maghemite iron oxide and sucrose under an argon atmosphere and subsequent oxidation in air. The nanocomposi...
2108.11314v1
2021-08-25
Magnetic properties of BiFeO$_3$-BaTiO$_3$ ceramics in the morphotropic phase boundary: a role of crystal structure and structural parameters
A correlation between the crystal structure and magnetic properties of system (1-x)BiFeO$_3$-(x)BaTiO$_3$ with compounds across the morphotropic phase boundary was studied using X-ray and neutron diffraction, magnetometry, and Mossbauer spectroscopy measurements. Increase in the dopants content leads to the structural ...
2108.11447v1
2021-08-30
Thermodynamic Signatures of Diagonal Nematicity in RbFe$_2$As$_2$ Superconductor
Electronic nematic states with broken rotational symmetry often emerge in correlated materials. In most iron-based superconductors, the nematic anisotropy is oriented in the Fe-Fe direction of the iron square lattice. Recently, a novel type of nematicity along the diagonal Fe-As direction has been suggested in heavily ...
2108.13081v1
2021-09-03
A stellar census in globular clusters with MUSE. A new perspective on the multiple main sequences of $ω$ Centauri
$\omega$ Cen is a rare example of a globular cluster where the iron abundance of the stars spans more than one order of magnitude. Many spectroscopic investigations of its red-giant- and sub-giant- branches have revealed multiple peaks in the iron abundance distribution. The metallicity distribution of main-sequence (M...
2109.01540v2
2021-09-09
Collisional mixing between inner and outer solar system planetesimals inferred from the Nedagolla iron meteorite
The ungrouped iron meteorite Nedagolla is the first meteorite with bulk Mo, Ru, and Ni isotopic compositions that are intermediate between those of the non-carbonaceous (NC) and carbonaceous (CC) meteorite reservoirs. The Hf-W chronology of Nedagolla indicates that this mixed NC-CC isotopic composition was established ...
2109.04224v1
2021-09-11
NuSTAR monitoring of MAXI J1348-630: evidence of high density disc reflection
We present the broadband spectral analysis of all the six hard, intermediate and soft state NuSTAR observations of the recently discovered transient black hole X-ray binary MAXI J1348-630 during its first outburst in 2019. We first model the data with a combination of a multi-colour disc and a relativistic blurred refl...
2109.05380v1
2021-09-14
Ultrafast Optical Spectroscopy Evidence of Pseudogap and Electron-Phonon Coupling in an Iron-Based Superconductor KCa$_2$Fe$_4$As$_4$F$_2$
We use ultrafast optical spectroscopy to study the nonequilibrium quasiparticle relaxation dynamics of the iron-based superconductor KCa$_2$Fe$_4$As$_4$F$_2$ with $T_c=33.5$ K. Our results reveal a possible pseudogap ($\Delta_{PG}$ = 2.4 $\pm$ 0.1 meV) below $T^*\approx 50$ K but prior to the opening of a superconducti...
2109.06460v2
2021-09-27
The Three-Dimensional Electronic Structure of LiFeAs: Strong-coupling Superconductivity and Topology in the Iron Pnictides
Amongst the iron-based superconductors, LiFeAs is unrivalled in the simplicity of its crystal structure and phase diagram. However, our understanding of this canonical compound suffers from conflict between mutually incompatible descriptions of the material's electronic structure, as derived from contradictory interpre...
2109.13276v1
2021-10-12
Vortex dynamics and second magnetization peak in the iron-pnictide superconductor Ca$_{0.82}$La$_{0.18}$Fe$_{0.96}$Ni$_{0.04}$As$_2$
We report the studies of detailed magnetic relaxation and isothermal magnetization measurements in the vortex state of the 112-type iron-pnictide Ca$_{0.82}$La$_{0.18}$Fe$_{0.96}$Ni$_{0.04}$As$_2$ superconductor with $T_c$ $\sim$ 22 K. In the isothermal $M(H)$, a well defined second magnetization peak (SMP) feature is ...
2110.05677v1
2021-10-19
Generalized estimates for the density of oxide scale in the range from 0 C to 1300 C
Oxide scale formed on the surface of steel products during high-teperature processes is studied as a composite material, the main solid components of which, in general, are wustite, magnetite, hematite and metallic iron. To estimate the density of each of these components in the temperature range from 0 C to 1300 C, fo...
2110.09791v1
2021-10-26
Stochastic Low Frequency Variability in 3-Dimensional Radiation Hydrodynamical Models of Massive Star Envelopes
Increasing main sequence stellar luminosity with stellar mass leads to the eventual dominance of radiation pressure in stellar envelope hydrostatic balance. As the luminosity approaches the Eddington limit, additional instabilities (beyond conventional convection) can occur. These instabilities readily manifest in the ...
2110.13944v1
2021-12-01
Orbital-Selective High-Temperature Cooper Pairing Developed in the Two-Dimensional Limit
The orbital multiplicity in multiband superconductors yields orbital differentiation in normal-state properties, and can lead to orbital-selective spin-fluctuation Cooper pairing. This phenomenon has become increasingly pivotal in clarifying the pairing 'enigma' particularly for multiband high-temperature superconducto...
2112.00383v1
2021-12-05
Optical singly-ionized iron emission in radio-quiet and relativistically jetted active galactic nuclei
The issue of the difference between optical and UV properties of radio-quiet and radio-loud (relativistically "jetted") active galactic nuclei (AGN) is a long standing one, related to the fundamental question of why a minority of powerful AGN possess strong radio emission due to relativistic ejections. This paper exami...
2112.02632v1
2021-12-10
Random-strain-induced correlations in materials with intertwined nematic and magnetic orders
Electronic nematicity is rarely observed as an isolated instability of a correlated electron system. Instead, in iron pnictides and in certain cuprates and heavy-fermion materials, nematicity is intertwined with an underlying spin-stripe or charge-stripe state. As a result, random strain, ubiquitous in any real crystal...
2112.05769v1
2021-12-15
A Suzaku sample of unabsorbed narrow-line and broad-line Seyfert 1 galaxies: II. Iron emission and absorption
A sample of 22 narrow-line Seyfert 1 (NLS1) and 47 broad-line Seyfert 1 (BLS1) galaxies observed with Suzaku is used to examine the Fe K band properties of each group. Three different models are used to examine the presence of: narrow neutral Fe Ka line at 6.4 keV and ionised Fe xxv and Fe xxvi emission lines (model A)...
2112.08127v1
2021-12-15
Stellar population astrophysics (SPA) with the TNG -- The chemical content of the red supergiant population in the Perseus complex
Context. The Perseus complex in the outer disk of the Galaxy hosts a number of clusters and associations of young stars. Gaia is providing a detailed characterization of their kinematic structure and evolutionary properties. Aims. Within the SPA Large Programme at the TNG, we secured HARPS-N and GIANO-B high-resolution...
2112.08402v1
2021-12-28
Simulations of globular clusters within their parent galaxies: Metallicity spreads and anomalous precursor populations
Recent observations of globular clusters (GCs) suggest that elemental abundance variations may exist between first-generation (1G) stars. We propose that metal abundance ('metallicity') spreads within GC forming giant molecular clouds (GMCs) can influence the iron abundances of future cluster members. To investigate th...
2112.13971v1
2022-01-04
Reconstruction of Air-Shower Parameters Through the Lateral Distribution Function of Ultra-High Energy Particles
In this study, the necessity of the simulation study for exploring the interactions of ultra-high energy particles cosmic rays was examined. Different hadronic interaction models such as (SIBYLL, QGSJET, and EPOS) were simulated by using air showers simulation AIRES system (version 19.04.00). Also, the charged particle...
2201.01368v1
2022-02-01
Optical Properties of C$-$rich ($^{12}$C, SiC and FeC) Dust Layered Structure of Massive Stars
The composition and structure of interstellar dust are important and complex for the study of the evolution of stars and the \textbf{interstellar medium} (ISM). However, there is a lack of corresponding experimental data and model theories. By theoretical calculations based on ab-initio method, we have predicted and ge...
2202.00260v1
2022-01-30
Ultrahigh-Pressure Magnesium Hydrosilicates as Reservoirs of Water in Early Earth
The origin of water on the Earth is a long-standing mystery, requiring a comprehensive search for hydrous compounds, stable at conditions of the deep Earth and made of Earth-abundant elements. Previous studies usually focused on the current range of pressure-temperature conditions in the Earth's mantle and ignored a po...
2202.00752v1
2022-03-30
The Chemical Composition of Extreme-Velocity Stars
Little is known about the origin of the fastest stars in the Galaxy. Our understanding of the Milky Way and surrounding dwarf galaxies chemical evolution history allows us to use the chemical composition of a star to investigate its origin, and say whether a star was formed in-situ or was accreted. However, the fastest...
2203.16364v1
2022-04-08
Estimation of Nitrogen-to-Iron Abundance Ratios From Low-Resolution Spectra
We present a method to determine nitrogen abundance ratios with respect to iron ([N/Fe]) from molecular CN-band features observed in low-resolution ($R \sim$ 2000) stellar spectra obtained by the Sloan Digital Sky Survey (SDSS) and the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST). Various tests ar...
2204.03933v1
2022-04-08
Possible Implications of Relatively High Levels of Initial $^{60}$Fe in Iron Meteorites for the Non-Carbonaceous -- Carbonaceous Meteorite Dichotomy and Solar Nebula Formation
Cook et al. (2021) found that iron meteorites have an initial abundance ratio of the short-lived isotope $^{60}$Fe to the stable isotope $^{56}$Fe of $^{60}$Fe/$^{56}$Fe $\sim$ $(6.4 \pm 2.0) \times 10^{-7}$. This appears to require the injection of live $^{60}$Fe from a Type II supernova (SN II) into the presolar mole...
2204.04134v1
2022-04-21
Ferrous Metal Matrix Composites Status Scope and Challenges
The present paper is an effort to culminate the status, scopes and challenges in the development of ferrous metal matrix composites (FMMCs). The FMMCs are old but less in use than the non-ferrous metal matrix composites (NFMMCs), as far as literature and actual applications are concerned. Therefore, this stimulates the...
2204.09999v2
2022-04-21
Detection of CO emission lines in the dayside atmospheres of WASP-33b and WASP-189b with GIANO
Ultra-hot Jupiters (UHJs) are expected to possess temperature inversion layers in their dayside atmospheres. Recent thermal emission observations have discovered several atomic and molecular species along with temperature inversions in UHJs. We observed the thermal emission spectra of two UHJs (WASP-33b and WASP-189b) ...
2204.10158v1
2022-05-17
A Disc Reflection Model for Ultra-Soft Narrow-Line Seyfert 1 Galaxies
We present a detailed analysis of the XMM-Newton observations of five narrow-line Seyfert 1 galaxies (NLS1s). They all show very soft continuum emission in the X-ray band with a photon index of $\Gamma\gtrsim 2.5$. Therefore, they are referred to as `ultra-soft' NLS1s in this paper. By modeling their optical/UV-X-ray s...
2205.08236v1
2022-05-28
Spectral Evidence for Unidirectional Charge Density Wave in Detwinned BaNi$_2$As$_2$
The emergence of unconventional superconductivity in proximity to intertwined electronic orders is especially relevant in the case of iron-based superconductors. Such order consists of an electronic nematic order and a spin density wave in these systems. BaNi$_2$As$_2$, like its well-known iron-based analog BaFe$_2$As$...
2205.14339v1
2022-06-02
Lithium detection in red supergiant stars of the Perseus complex
We present the first systematic study of lithium abundance in a chemically homogeneous sample of 27 red supergiants (RSGs) in the young Perseus complex. For these stars, accurate stellar parameters and detailed chemical abundances of iron and iron peak, CNO, alpha, light and neutron-capture elements have been already o...
2206.01218v1
2022-06-15
Hyperfine fields at $^{66}$Ga, $^{67,69}$Ge implanted into iron and gadolinium hosts at 6 K, and applications to g-factor measurements
Isomers in $^{66}$Ga, $^{67}$Ge, and $^{69}$Ge were recoil-implanted into ferromagnetic hosts of iron and gadolinium at $\approx 6$~K, and the hyperfine magnetic fields were determined by Time Differential Perturbed Angular Distribution (TDPAD) measurements. The hyperfine field strengths at $\approx 6$~K are compared t...
2206.07294v1
2022-06-23
Size-dependent Failure Behavior of Lithium-Iron Phosphate Battery under Mechanical Abuse
Under mechanical abuse conditions, the failure of lithium-ion batteries occurs in various stages characterized by different force, temperature and voltage response which require it's in-situ measurements for analysis. Firstly, four sizes of commercially available lithium-iron phosphate batteries (LFPB) viz. 18650, 2265...
2206.11732v2
2022-08-03
Light-induced dynamics of liquid-crystalline droplets on the surface of iron-doped lithium niobate crystals
We investigated the effect of a photovoltaic field generated on the surface of iron-doped lithium niobate crystals on droplets of a ferroelectric nematic liquid crystalline and a standard nematic liquid crystalline material deposited on this surface. When such assembly is illuminated with a laser beam, a wide range of ...
2208.02318v1
2022-09-07
Transport evidence for the surface state and spin-phonon interaction in FeTe$_{0.5}$Se$_{0.5}$
The iron chalcogenides have been proved to be intrinsic topological superconductors to implement quantum computation because of their unique electronic structures. The topologically nontrivial surface states of FeTe$_{0.5}$Se$_{0.5}$ have been predicted by several calculations and then confirmed by high-resolution phot...
2209.03267v2
2022-09-14
Structural peculiarities of $\varepsilon$-Fe$_2$O$_3$ / GaN epitaxial layers unveiled by high-resolution transmission electron microscopy and neutron reflectometry
The present paper is dedicated to the structural study of crystallographic peculiarities appearing in epitaxial films of metastable epsilon iron oxide ($\varepsilon$-Fe$_2$O$_3$) grown by pulsed laser deposition onto a semiconductor GaN (0001) substrate. The columnar structure of the nanoscale $\varepsilon$-Fe$_2$O$_3$...
2209.06460v1
2022-09-15
Spin-charge coupling and decoupling in perovskite-type iron oxides (Sr$_{1-x}$Ba$_x$)$_{2/3}$La$_{1/3}$FeO$_3$
The perovskite-type iron oxide Sr$_{2/3}$La$_{1/3}$FeO$_3$ is known to show characteristic spin-charge ordering (SCO), where sixfold collinear spin ordering and threefold charge ordering are coupled with each other. Here, we report the discovery of a spin-charge decoupling and an antiferromagnetic (AFM) state competing...
2209.07310v1
2022-09-18
Revisit the Circumnuclear X-ray Emission of NGC 2992 in a Historically Low State
The inner-most region of the Seyfert galaxy NGC 2992 has long been suspected to be the location of intense AGN-host galaxy interaction, but photon pile-up in previous high-resolution observations hampered the study of soft X-ray excess and the interaction near its nucleus. We present an X-ray imaging spectroscopic anal...
2209.08534v1
2022-09-18
Efficient photocatalytic nitrogen fixation from air under sunlight via iron-doped WO$_3$
Photocatalytic nitrogen fixation from air directly under sunlight can contribute significantly to carbon neutralization. It is an ideal pathway to replace the industrial Haber Bosch process in future. A Fe-doped layered WO$_3$ photocatalyst containing oxygen vacancies was developed which can fix nitrogen from air direc...
2209.08547v1
2022-09-30
Charge Transport in Ba$_{1-x}$Rb$_{x}$Fe$_{2}$As$_{2}$ Single Crystals
Recent studies in heavily hole-doped iron-based superconductor RbFe$_2$As$_2$ have suggested the emergence of novel electronic nematicity directed along the Fe-As direction, 45$^\circ$ rotated from the usual nematicity ubiquitously found in BaFe$_2$As$_2$ and related materials. This motivates us to study the physical p...
2209.15526v1
2022-10-20
Kinetics of transformation, border of metastable miscibility gap in Fe-Cr alloy and limit of Cr solubility in iron at 858 K
The study was aimed at determination of the position of the Fe-rich border of the metastable miscibility gap (MMG) and of the solubility limit of Cr in iron at 858 K. Towards this end a Fe73.7Cr26.3 alloy was isothermally annealed at 858 K in vacuum up to 8144 hours and M\"ossbauer spectra were recorded at room tempera...
2210.11550v1
2022-11-04
Unusual Abundances from Planetary System Material Polluting the White Dwarf G238-44
Ultraviolet and optical spectra of the hydrogen-dominated atmosphere white dwarf star G238-44 obtained with FUSE, Keck/HIRES, HST/COS, and HST/STIS reveal ten elements heavier than helium: C, N, O, Mg, Al, Si, P, S, Ca, and Fe. G238-44 is only the third white dwarf with nitrogen detected in its atmosphere from pollutin...
2211.02673v1
2022-11-09
Asynchronous accretion can mimic diverse white dwarf pollutants I: core and mantle fragments
Polluted white dwarfs serve as astrophysical mass spectrometers - their photospheric abundances are used to infer the composition of planetary objects that accrete onto them. We show that due to asymmetries in the accretion process, the composition of the material falling onto a star may vary with time during the accre...
2211.05114v1
2022-11-21
Discontinuous Shear Thickening (DST) transition with spherical iron particles coated by adsorbed brush polymer
In this work we explore the rheology of very concentrated (0.55<$\Phi$<0.67) suspensions of carbonyl iron (CI) particles coated by a small polymer. A strong DST is observed in a large range of volume fraction presenting some specificities relatively to other systems. In particular, in a given range of volume fraction, ...
2211.11807v1
2022-12-03
Electron correlation in the Iron(II) Porphyrin by NOF approximations
The relative stability of the singlet, triplet, and quintet spin states of Iron(II) porphyrin (FeP) represents a challenging problem for electronic structure methods. While it is currently accepted that the ground state is a triplet, multiconfigurational wavefunction-based methods predict a quintet, and density functio...
2212.01640v1
2022-12-13
Collapse of Metallicity and High-$T_c$ Superconductivity in the High-Pressure phase of FeSe$_{0.89}$S$_{0.11}$
We investigate the high-pressure phase of the iron-based superconductor FeSe$_{0.89}$S$_{0.11}$ using transport and tunnel diode oscillator studies. We construct detailed pressure-temperature phase diagrams that indicate that outside of the nematic phase, the superconducting critical temperature reaches a minimum befor...
2212.06824v1
2022-12-21
Post-Synthetic Treatment of Nickel-Iron Layered Double Hydroxides for the Optimum Catalysis of the Oxygen Evolution Reaction
Nickel-iron layered double hydroxide (NiFe LDH) platelets with high morphological regularity and sub-micrometre lateral dimensions were synthesized using a homogeneous precipitation technique for highly efficient catalysis of the oxygen evolution reaction (OER). Considering edge sites are the point of activity, efforts...
2212.11378v1
2023-01-03
Extracting optical parameters of Cu-Mn-Fe spinel oxide nanoparticles for optimizing air-stable, high-efficiency solar selective coatings
High-temperature Cu-Mn-Fe spinel-oxide nanoparticle solar selective absorber coatings are investigated experimentally and theoretically. A reliable, general approach to evaluate absorption coefficient spectra from the optical measurements of the nanoparticle-pigmented coatings is developed based on solving the inverse ...
2301.01194v1
2023-01-07
Orthogonal magnetic structures of Fe4O5:representation analysis and DFT calculations
The magnetic and electronic structures of Fe4O5 have been investigated at ambient and high pressures via a combination of representation analysis, density functional theory (DFT+U) calculations, and M\"ossbauer spectroscopy. A few spin configurations corresponding to the different irreducible representations have been ...
2301.02824v1
2023-02-03
An empirical relation to estimate host galaxy stellar light from AGN spectra
Measurement of black hole mass for low-$z$ ($z\leq 0.8$) Active Galactic Nuclei (AGNs) is difficult due to the strong contribution from host galaxy stellar light necessitating detailed spectral decomposition to estimate the AGN luminosity. Here, we present an empirical relation to estimate host galaxy stellar luminosit...
2302.01948v2
2023-02-13
Evolution of phase morphology in dispersed clay systems under the microwave irradiation
The results of a study of the effect of microvolume emission (power 700 W, frequency 2.45 GHz) on the structural changes in natural clay particles are presented. The influence of the irradiation time (10 and 20 minutes) and the environment in the microwave chamber (atmospheric air and air saturated with water vapor) on...
2302.06330v1
2023-03-01
A Search for Chemical Anomalies of Seven A-types Stars
We present a chemical abundance analysis of seven A-type stars with no detailed chemical abundance measurements in the literature. High-resolution spectra of the targets HD 2924, HD 4321, HD 26553, HD 125658, HD 137928, HD 154713, and HD 159834 were obtained using the Coude Echelle Spectrograph at the TUBITAK National ...
2303.00584v1
2023-05-29
Intertwined charge and pair density orders in a monolayer high-Tc iron-based superconductor
Symmetry-breaking electronic phase in unconventional high-temperature (high-Tc) superconductors is a fascinating issue in condensed-matter physics, among which the most attractive phases are charge density wave (CDW) phase with four unit-cell periodicity in cuprates and nematic phase breaking the C4 rotational symmetry...
2305.17991v1
2023-06-22
Type Ia Supernova Nucleosynthesis: Metallicity-Dependent Yields
Type Ia supernova explosions (SNIa) are fundamental sources of elements for the chemical evolution of galaxies. They efficiently produce intermediate-mass (with Z between 11 and 20) and iron group elements - for example, about 70% of the solar iron is expected to be made by SNIa. In this work, we calculate complete abu...
2306.12885v1
2023-06-27
Permanent magnet systems to study the interaction between magnetic nanoparticles and cells in microslide channels
We optimized designs of permanent magnet systems to study the effect of magnetic nanoparticles on cell cultures in microslide channels. This produced two designs, one of which is based on a large cylindrical magnet that applies a uniform force density of 6 MN/m$^3$ on soft magnetic iron-oxide spherical nanoparticles at...
2306.15459v2
2023-07-10
Design and processing as ultrathin films of a sublimable Iron(II) spin crossover material exhibiting efficient and fast light-induced spin transition
Materials based on spin crossover (SCO) molecules have centred the attention in Molecular Magnetism for more than forty years as they provide unique examples of multifunctional and stimuli-responsive materials, which can be then integrated into electronic devices to exploit their molecular bistability. This process oft...
2307.04591v1
2023-07-17
Controlling the Temperature of the Spin-Reorientation Transition In HoFe1-xMnxO3 Orthoferrite Single Crystals
HoFe1-xMnxO3 (0 < x < 1) single crystals have been grown by the optical floating zone technique. A structural transition from the orthorhombic to hexagonal modification has been established in the crystals in the concentration range of 0.7-0.8, which has been confirmed by the X-ray diffraction data. For a series of the...
2307.08236v1
2023-07-19
Origin of Life Molecules in the Atmosphere After Big Impacts on the Early Earth
The origin of life on Earth would benefit from a prebiotic atmosphere that produced nitriles, like HCN, which enable ribonucleotide synthesis. However, geochemical evidence suggests that Hadean air was relatively oxidizing with negligible photochemical production of prebiotic molecules. These paradoxes are resolved by ...
2307.09761v1
2023-07-28
Structural phase transition, $s_{\pm}$-wave pairing and magnetic stripe order in the bilayered nickelate superconductor La$_3$Ni$_2$O$_7$ under pressure
Motivated by the recently discovered high-$T_c$ superconductor La$_3$Ni$_2$O$_7$, we comprehensively study this system using density functional theory and random phase approximation calculations. At low pressures, the Amam phase is stable, containing the Y$^{2-}$ mode distortion from the Fmmm phase, while the Fmmm phas...
2307.15276v4
2023-08-01
The current state of disk wind observations in BHLMXBs through X-ray absorption lines in the iron band
The presence of blueshifted absorption lines in the X-ray spectra of Black Hole Low Mass X-ray Binaries is the telltale of massive outflows called winds. These signatures are found almost exclusively in soft states of high-inclined systems, hinting at equatorial ejections originating from the accretion disk and deeply ...
2308.00691v1
2023-08-07
Energy-resolved pulse profiles of accreting pulsars: Diagnostic tools for spectral features
We introduce a method for extracting spectral information from energy-resolved light curves folded at the neutron star spin period (known as pulse profiles) in accreting X-ray binaries. Spectra of these sources are sometimes characterized by features superimposed on a smooth continuum, such as iron emission lines and c...
2308.03395v1
2023-08-08
Designing optoelectronic properties by on-surface synthesis: formation and electronic structure of an iron-terpyridine macromolecular complex
Supramolecular chemistry protocols applied on surfaces offer compelling avenues for atomic scale control over organic-inorganic interface structures. In this approach, adsorbate-surface interactions and two-dimensional confinement can lead to morphologies and properties that differ dramatically from those achieved via ...
2308.04105v1
2023-09-05
Magnetic and structural properties of the iron silicide superconductor LaFeSiH
The magnetic and structural properties of the recently discovered pnictogen/chalcogen-free superconductor LaFeSiH ($T_c\simeq10$~K) have been investigated by $^{57}$Fe synchrotron M{\"o}ssbauer source (SMS) spectroscopy, x-ray and neutron powder diffraction and $^{29}$Si nuclear magnetic resonance spectroscopy (NMR). N...
2309.02241v1
2023-09-15
Superconductivity and vortex structure on Bi$_{2}$Te$_{3}$/FeTe$_{0.55}$Se$_{0.45}$ heterostructures with different thickness of Bi$_{2}$Te$_{3}$ films
Using scanning tunnel microscopy (STM), we investigate the superconductivity and vortex properties in topological insulator Bi$_{2}$Te$_{3}$ thin films grown on the iron-based superconductor FeTe$_{0.55}$Se$_{0.45}$. The proximity-induced superconductivity weakens in the Bi$_{2}$Te$_{3}$ film when the thickness of the ...
2309.08246v1
2023-09-22
Wavelet spectral timing: X-ray reverberation from a dynamic black hole corona hidden beneath ultrafast outflows
Spectral timing analyses based upon wavelet transforms provide a new means to study the variability of the X-ray emission from accreting systems, including AGN, stellar mass black holes and neutron stars, and can be used to trace the time variability of X-ray reverberation from the inner accretion disc. The previously-...
2309.13107v2
2023-10-13
Polarized microwave emission from space particles in the upper atmosphere of the Earth
Tons of space particles enter the Earth atmosphere every year, being detected when they produce fireballs, meteor showers, or when they impact the Earth surface. Particle detection in the showers could also be attempted from space using satellites in low Earth orbit. Measuring the polarization would provide extra cruci...
2310.08941v1
2023-10-17
Towards atomistic understanding of Iron phosphate glass: a first-principles based DFT modeling and study of its physical properties
Iron phosphate glasses (IPG) have been proposed as futuristic glass material for nuclear waste immobilization, anode material for lithium batteries and also as bioactive glass. In the last decade, there have been attempts to propose atomistic models of IPG to explain their properties from atomistic viewpoint and to pre...
2310.11135v1
2023-10-25
Post-main sequence thermal evolution of planetesimals
White dwarfs that have accreted planetary materials provide a powerful tool to probe the interiors and formation of exoplanets. In particular, the high Fe/Si ratio of some white dwarf pollutants suggests that they are fragments of bodies that were heated enough to undergo large-scale melting and iron core formation. In...
2310.17057v1
2023-10-26
Honing cross-correlation tools for inference on ultra-high-energy cosmic-ray composition
The chemical composition of the highest-energy cosmic rays, namely the atomic number $Z$ of rays with energies $E\gg1~\text{EeV}$, remains to date largely unknown. Some information on the composition can be inferred from the deflections that charged ultra-high-energy cosmic rays experience while they traverse interveni...
2310.17699v2
2023-10-31
Chemical evolution models: the role of type Ia supernovae in the $α$-elements over Iron relative abundances and their variations in time and space
The role of type Ia supernovae, mainly the Delay Time Distributions (DTDs) determined by the binary systems, and the yields of elements created by different explosion mechanisms, are studied by using the {\sc MulChem} chemical evolution model, applied to our Galaxy. We explored 15 DTDs, and 12 tables of elemental yield...
2311.00076v1
2023-11-01
Annealing effects on the magnetic and magnetotransport properties of iron oxide nanoparticles self-assemblies
In magnetic tunnel junctions based on iron oxide nanoparticles the disorder and the oxidation state of the surface spin as well as the nanoparticles functionalization play a crucial role in the magnetotransport properties. In this work, we report a systematic study of the effects of vacuum annealing on the structural, ...
2311.00700v1
2023-11-10
Enhancement of optical absorption in multiferroic (1-x)PZT-xPFN thin films: Experiments and first-principles analysis
Multiferroic compounds have gained research attention in the field of ferroelectric photovoltaics due to the presence of transition-metal d states from magnetic ions, which tend to reduce the bandgap value. In this work, 0.5Pb(Zr0.52Ti0.48)O3 - 0.5Pb(Fe0.5Nb0.5)O3 PZTFN0.5 thin films were synthesized using a sol-gel ro...
2311.05855v1
2023-11-14
Superconductivity with $T_c$ up to 30.7 K in air-annealed CaFeAsF
Exploring new unconventional superconductors is of great value for both fundamental research and practical applications. It is a long-term challenge to develop and study more hole-doped superconductors in 1111 system of iron-based superconductors. However, fifteen years after the discovery of iron-based superconductors...
2311.07943v1
2023-12-14
X-ray Reflection from the Plunging Region of Black Hole Accretion Disks
Accretion around black holes is very often characterized by distinctive X-ray reflection features (mostly, iron inner-shell transitions), which arise due to the primary radiation being reprocessed by a dense and relatively colder medium, such as an accretion disk. Most reflection modeling assume that emission stops at ...
2312.09210v1
2024-01-05
Joint analysis of the iron emission in the optical and near-infrared spectrum of I Zw 1
Constraining the physical conditions of the ionized media in the vicinity of an active supermassive black hole (SMBH) is crucial to understanding how these complex systems operate. Metal emission lines such as iron (Fe) are useful probes to trace the gaseous media's abundance, activity, and evolution in these accreting...
2401.02936v1
2024-01-16
Bias-Compensated State of Charge and State of Health Joint Estimation for Lithium Iron Phosphate Batteries
Accurate estimation of the state of charge (SOC) and state of health (SOH) is crucial for the safe and reliable operation of batteries. Voltage measurement bias highly affects state estimation accuracy, especially in Lithium Iron Phosphate (LFP) batteries, which are susceptible due to their flat open-circuit voltage (O...
2401.08136v2
2024-01-19
Reflecting on naked singularities: iron line fitting as a probe of the cosmic censorship conjecture
We demonstrate that the X-ray iron line fitting technique can be leveraged as a powerful probe of the cosmic censorship conjecture. We do this by extending existing emission line models to arbitrary spin parameters of the Kerr metric, no longer restricted to black hole metrics with $|a_\bullet |< 1$. We show that the e...
2401.10565v1
2024-01-25
Nucleosynthesis in magnetorotational supernovae: impact of the magnetic field configuration
The production of heavy elements is one of the main by-products of the explosive end of massive stars. A long sought goal is finding differentiated patterns in the nucleosynthesis yields, which could permit identifying a number of properties of the explosive core. Among them, the traces of the magnetic field topology a...
2401.14402v1
2024-02-15
A variable ionized disk wind in MAXI J1803-298 revealed by NICER
We present the results from the NICER observation data of MAXI J1803-298 across the entire 2021 outburst. In the intermediate and soft state, we detect significant absorption lines at $\sim 7.0$ keV and $\sim 6.7$ keV, arising from the X-ray disk wind outflowing with a velocity of hundreds of km per second along our li...
2402.10315v1
2024-03-04
Interplay between alloying and tramp element effects on temper embrittlement in bcc iron: DFT and thermodynamic insights
The details of the temper embrittlement mechanism in steels caused by impurities are unknown. Especially from an atomistic point of view, there are still open questions regarding their interactions with alloying elements such as Ni, Cr, and Mo. Therefore, we used density functional theory to investigate the segregation...
2403.02186v1
2024-03-10
Conventional Superconductivity in the Doped Kagome Superconductor Cs(V0.86Ta0.14)3Sb5 from Vortex Lattice Studies
A hallmark of unconventional superconductors is their complex electronic phase diagrams where "intertwined orders" of charge-spin-lattice degrees of freedom compete and coexist as in copper oxides and iron pnictides. While the electronic phase diagram of kagome lattice superconductor such as CsV3Sb5 also exhibits compl...
2403.06046v1
2024-03-14
An FFT based approach to account for elastic interactions in OkMC: Application to dislocation loops in iron
Object kinetic Montecarlo (OkMC) is a fundamental tool for modeling defect evolution in volumes and times far beyond atomistic models. The elastic interaction between defects is classically considered using a dipolar approximation but this approach is limited to simple cases and can be inaccurate for large and close in...
2403.09158v1
2024-03-18
Primary Defect Production in Doped Iron Grain Boundaries during Low Energy Collision Cascades
This study explores the intricate interactions between grain boundaries (GBs) and irradiation-induced defects in nanocrystalline iron, highlighting the role of dopants like copper. Utilizing molecular dynamics simulations, the research delineates how GB properties, such as GB energy and defect formation energies, influ...
2403.12257v1
2022-04-02
Direct Measurement of the Nickel Spectrum in Cosmic Rays in the Energy Range from 8.8 GeV/n to 240 GeV/n with CALET on the International Space Station
The relative abundance of cosmic ray nickel nuclei with respect to iron is by far larger than for all other trans-iron elements, therefore it provides a favorable opportunity for a low background measurement of its spectrum. Since nickel, as well as iron, is one of the most stable nuclei, the nickel energy spectrum and...
2204.00845v1
2020-12-03
On the Use of Field RR Lyrae as Galactic Probes. II. A new $Δ$S calibration to estimate their metallicity
We performed the largest and most homogeneous spectroscopic survey of field RR Lyraes (RRLs). We secured $\approx$6,300 high resolution (HR, R$\sim$35,000) spectra for 143 RRLs (111 fundamental, RRab; 32 first overtone, RRc). The atmospheric parameters were estimated by using the traditional approach and the iron abund...
2012.02284v1