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2014-06-24
The Origin of the X-ray Emission from the High-velocity Cloud MS30.7-81.4-118
A soft X-ray enhancement has recently been reported toward the high-velocity cloud MS30.7-81.4-118 (MS30.7), a constituent of the Magellanic Stream. In order to investigate the origin of this enhancement, we have analyzed two overlapping XMM-Newton observations of this cloud. We find that the X-ray enhancement is $\sim...
1406.6363v1
2015-03-21
Graphene as a p-type metal for ultimate miniaturization
We report macroscopic sheets of highly conductive bilayer graphene with exceptionally high hole concentrations of ~ $10^{15}$ $cm^{-2}$ and unprecedented sheet resistances of 20-25 {\Omega} per square over macroscopic scales, and obtained in-situ over a thin cushion of molecular oxygen on a silicon substrate. The elect...
1503.06253v2
2018-04-06
Antisite pairs suppress the thermal conductivity of BAs
BAs was predicted to have an unusually high thermal conductivity at room temperature of 2000$\,$Wm$^{-1}$$\,$K$^{-1}$, comparable to that of diamond. However, the experimentally measured thermal conductivity of BAs single crystals is an order of magnitude lower. To identify the origin of this large inconsistency, we in...
1804.02381v1
2019-04-08
Characterizations of thermal stability and electrical performance of Au-Ni coating on CuCrZr substrate for high vacuum radio-frequency contact application
Radio-frequency (RF) contacts-which are an example of electrical contacts-are commonly employed on accelerators and nuclear fusion experimental devices. RF contacts with a current load of 2 kA for steady-state operation were designed for application to the International Thermonuclear Experimental Reactor (ITER) device....
1907.07236v1
2020-07-03
Enhanced creep performance in a polycrystalline superalloy driven by atomic-scale phase transformation along planar faults
Predicting the mechanical failure of parts in service requires understanding their deformation behavior, and associated dynamic microstructural evolution up to the near-atomic scale. Solutes are known to interact with defects generated by plastic deformation, thereby affecting their displacement throughout the microstr...
2007.01676v2
2022-03-15
Flexible terahertz photonic light-cage modules for in-core sensing and high temperature applications
Terahertz (THz) technology is a growing and multi-disciplinary research field, particularly for sensing and telecommunications. A number of THz waveguides have emerged over the past years, which are set to complement the capabilities of existing and bulky free space setups. In most designs however, the guiding region i...
2203.08316v1
2022-10-21
Understanding The Reversible Electrodeposition of Al in Low-Cost Room Temperature Molten Salts
Aluminum is the most earth-abundant metal, is trivalent, is inert in ambient humid air, and has a density approximately four-times that of lithium at room temperature. These attributes make it an attractive material for cost-effective, long-duration storage of electrical energy in batteries. Scientific discoveries in t...
2210.12131v1
2024-01-18
Spreading of Low-viscosity Ink Filaments Driven by Bath Viscoelasticity in Embedded Printing
Inks deposited in conventional direct ink writing need to be able to support their own weight and that of the upper layers with minimal deformation to preserve the structural integrity of the three-dimensional (3D) printed parts. This constraint limits the range of usable inks to high-viscosity materials. Embedded prin...
2401.09684v1
2001-10-08
Structural and electronic properties of the Nb$_4$-cluster compound Ga$_{1.33}$Nb$_4$X$_8$ (X = S, Se)
We report resistivity, thermopower and magnetic susceptibility measurements on the Nb$_4$-cluster compounds Ga$_{1.33}$Nb$_4$X$_{8}$ (X = S, Se), derived from vacancy ordered spinels A$_x$T$_4$X$_8$. The cubic selenide phase is insulating and its resistivity crosses over from $\ln{\rho} \sim T^{-1}$ to $\sim T^{-1/2}$ ...
0110155v1
2001-11-06
Spin-dependent electrical transport in ion-beam sputter deposited Fe-Cr multilayers
The temperature dependence of the electrical resistivity and magnetoresistance of Xe-ion beam sputtered Fe-Cr multilayers has been investigated. The electrical resistivity between 5 and 300 K in the fully ferromagnetic state, obtained by applying a field beyond the saturation field (H_sat) necessary for the antiferroma...
0111084v1
2002-10-29
Quantum Resistive Behaviors in the Vortex Liquid Regimes at Finite Temperatures
Motivated by a {\it mean field-like} resistive behavior in magnetic fields commonly seen in various superconducting (SC) cuprates and organics with strong fluctuation, {\it quantum} SC fluctuation effects on resistive behaviors are reexamined by putting emphasis on their roles in the so-called {\it thermal} vortex liqu...
0210626v5
2002-11-22
Room Temperature Ballistic Conduction in Carbon Nanotubes
Multiwalled carbon nanotubes are shown to be ballistic conductors at room temperature, with mean free paths of the order of tens of microns. These experiments follow and extend the original experiments by Frank et al (Science, 280 1744 1998) including in-situ electron microscopy experiments and a detailed analysis of t...
0211515v1
2006-12-27
Peculiarities of the transport properties of InMnAs layers, produced by the laser deposition, in strong magnetic fields
Magnetotransport properties of p-InMnAs layers are studied in pulsed magnetic fields up to 30 T. Samples were prepared by the laser deposition and annealed by ruby laser pulses. Well annealed samples show p-type conductivity while they were n-type before the annealing. Surprisingly the anomalous Hall effect resistance ...
0612641v1
2007-06-28
Emergence of a flux tube through a partially ionised solar atmosphere
For a magnetic flux tube, or indeed any flux, to emerge into the Solar corona from the convection zone it must pass through the partially ionised layers of the lower atmosphere: the photosphere and the chromosphere. In such regions the ion-neutral collisions lead to an increased resistivity for currents flowing across ...
0706.4223v1
2010-01-10
Anomalies of conductivity behavior near the paramagnetic-antiferromagnetic transition in single-crystals La_{2}CuO_{4+δ}
The temperature dependences of resistance, R(T), of two single-crystals La_{2}CuO_{4+\delta} samples have been studied with the aim to detect a possible change in the R(T) behavior induced by paramagnetic-antiferromagnetic (PM-AFM) transition. One of the samples with \delta \lesssim 0.01, was fairly homogeneous in oxyg...
1001.1518v1
2011-05-07
Effect of 50 MeV Li3+ irradiation on structural and electrical properties of Mn doped ZnO
The present work aims to study the effect of ion irradiation on structural and electrical properties and their correlation with the defects in Zn1-xMnxO type system. Zn1-xMnxO (x = 0.02, 0.04) samples have been synthesized by solid-state reaction method and have been irradiated with 50 MeV Li3+ ions. The concomitant ch...
1105.1414v1
2013-01-07
Disorder-driven carrier transport in atomic layer deposited ZnO thin films
This paper addresses the effect of disorder on the carrier transport mechanism of atomic layer deposited ZnO thin films as has been investigated by temperature dependent electrical resistivity measurements in the temperature range of 4.2K to 300K. Films were grown on (0001) sapphire substrate at different substrate tem...
1301.1172v1
2014-11-27
Temperature dependence of electrical and thermal conduction in single silver nanowire
Silver nanowires have great application potential in fields like flexible electronic devices, solar cells and transparent electrodes. It is critical and fundamental to study the thermal and electrical transport properties in a single silver nanowire. In this work, the thermal and electrical transport in an individual s...
1411.7659v2
2015-09-18
Evidence for hydrodynamic electron flow in PdCoO$_2$
Electron transport is conventionally determined by the momentum-relaxing scattering of electrons by the host solid and its excitations. The electrical resistance is set by geometrical factors and the resistivity, which is a microscopic property of the solid. Hydrodynamic fluid flow through channels, in contrast, is det...
1509.05691v2
2015-10-31
The influence of system dynamics on the frictional resistance: insights from a discrete model
In order to examine the influence of system dynamics on sliding friction, we introduce the so-called micro-walking machine. This model consists of a rigid body with a number of elastic contact spots that is pulled by a constantly moving base. The system slides with dry friction on a rigid substrate. The kinematic coupl...
1511.00162v1
2016-05-02
Interfilament Resistance at 77 K in Striated HTS Coated Conductors
Striating HTS coated conductor (CC) tapes into narrow filaments offers the possibility of reducing the tapes' magnetization losses without unreasonably decreasing their current-carrying capability. However, realizing well-separated striations presents technological challenges, especially if the number of filaments is l...
1605.00401v2
2016-08-09
Disorder-sensitive pump-probe measurements on Nd$_{1.83}$Ce$_{0.17}$CuO$_{4\pmδ}$ films
We find an unambiguous relationship between disorder-driven features in the temperature dependence of the resistance and the behavior, as functions of the temperature, of the parameters necessary to describe some of the relaxation processes in the photoinduced differential time-resolved reflectivity of three samples of...
1608.03006v1
2018-05-10
Activation Energy of Metastable Amorphous Ge2Sb2Te5 from Room Temperature to Melt
Resistivity of metastable amorphous Ge2Sb2Te5 (GST) measured at device level show an exponential decline with temperature matching with the steady-state thin-film resistivity measured at 858 K (melting temperature). This suggests that the free carrier activation mechanisms form a continuum in a large temperature scale ...
1805.04054v1
2019-09-17
Algorithm for Training Neural Networks on Resistive Device Arrays
Hardware architectures composed of resistive cross-point device arrays can provide significant power and speed benefits for deep neural network training workloads using stochastic gradient descent (SGD) and backpropagation (BP) algorithm. The training accuracy on this imminent analog hardware however strongly depends o...
1909.07908v1
2017-04-13
Light Induced Electron-Phonon Scattering Mediated Resistive Switching in Nanostructured Nb Thin Film Superconductor
The elemental Nb is mainly investigated for its eminent superconducting properties. In contrary, we report of a relatively unexplored property, namely, its superior optoelectronic property in reduced dimension. We demonstrate here that nanostructured Nb thin films (NNFs), under optical illumination, behave as room temp...
1704.04092v1
2017-07-05
Anomalous Hall effect in two-dimensional non-collinear antiferromagnetic semiconductor Cr0.68Se
Cr0.68Se single crystals with two-dimensional (2D) character have been grown, and the detailed magnetization M(T), electrical transport properties (including longitudinal resistivity and Hall resistivity and thermal transport ones (including heat capacity Cp(T) and thermoelectric power (TEP) S(T)) have been measured. T...
1707.01252v1
2017-07-20
Stochastic Dynamics of Resistive Switching: Fluctuations Lead to Optimal Particle Number
Resistive switching is one of the foremost candidates for building novel types of non-volatile random access memories. Any practical implementation of such a memory cell calls for a strong miniaturization, at which point fluctuations start playing a role that cannot be neglected. A detailed understanding of switching m...
1707.06648v1
2018-08-02
Non-Classical Longitudinal Magneto-Resistance in Anisotropic Black Phosphorus
Resistivity measurements of a few-layer black phosphorus (bP) crystal in parallel magnetic fields up to 45 T are reported as a function of the angle between the in-plane field and the source-drain (S-D) axis of the device. The crystallographic directions of the bP crystal were determined by Raman spectroscopy, with the...
1808.00858v2
2019-08-12
The role of graphitic filaments in resistive switching behaviour of amorphous silicon carbide thin films
Resistive switching in amorphous silicon carbide (a-SiC) films deposited by a single composite target magnetron sputtering process is reported. Switching performance as a function of thickness of the films (50, 100 and 300 nm) as well as different top metal electrodes (Cu, Pt and Ag) with the bottom electrode fixed as ...
1908.04079v1
2018-07-13
Tuning vortex fluctuations and the resistive transition in superconducting films with a thin overlayer
It is shown that the temperature of the resistive transition $T_r$ of a superconducting film can be increased by a thin superconducting or normal overlayer. For instance, deposition of a highly conductive thin overlayer onto a dirty superconducting film can give rise to an "anti-proximity effect" which manifests itself...
1807.04891v1
2020-01-02
Numerical investigation into fracture resistance of bone following adaptation
Bone adapts in response to its mechanical environment. This evolution of bone density is one of the most important mechanisms for developing fracture resistance. A finite element framework for simulating bone adaptation, commonly called bone remodelling, is presented. This is followed by a novel method to both quantify...
2001.00647v1
2020-06-19
Contrasting physical properties of the trilayer nickelates Nd$_4$Ni$_3$O$_{10}$ and Nd$_4$Ni$_3$O$_8$
We report the crystal structures and physical properties of trilayer nickelates Nd$_4$Ni$_3$O$_{10}$ and Nd$_4$Ni$_3$O$_8$. Measurements of magnetization and electrical resistivity display contrasting behaviors in the two compounds. Nd$_4$Ni$_3$O$_{10}$ shows a paramagnetic metallic behavior with a metal to metal phase...
2006.10988v1
2020-10-13
How to solve problems in micro- and nanofabrication caused by the emission of electrons and charged metal atoms during e-beam evaporation
We discuss how the emission of electrons and ions during electron-beam-induced physical vapor deposition can cause problems in micro- and nanofabrication processes. After giving a short overview of different types of radiation emitted from an electron-beam (e-beam) evaporator and how the amount of radiation depends on ...
2010.06459v2
2021-02-17
Optimization of epitaxial graphene growth for quantum metrology
(See the complete abstract within the thesis in both English and German versions) In this thesis, the process conditions of the epitaxial graphene growth through a socalled polymer-assisted sublimation growth method are minutely investigated. Atomic force microscopy (AFM) is used to show that the previously neglected...
2102.08691v1
2021-05-30
Enhanced electron-phonon coupling in doubly aligned hexagonal boron nitride bilayer graphene heterostructure
The relative twist angle in heterostructures of two-dimensional (2D) materials with similar lattice constants result in a dramatic alteration of the electronic properties. Here, we investigate the electrical and magnetotransport properties in bilayer graphene (BLG) encapsulated between two hexagonal boron nitride (hBN)...
2105.14589v1
2021-09-01
Thickness dependent transition from the 1T$^\prime$ to Weyl semimetal phase in ultrathin MoTe$ _{2} $: Electrical transport, Noise and Raman studies
Bulk 1T$^\prime$-MoTe$_2$ shows a structural phase transition from 1T$^\prime$ to Weyl semimetallic (WSM) $ T_{d} $ phase at $\sim$ 240 K. This phase transition and transport properties in the two phases have not been investigated on ultra-thin crystals. Here we report electrical transport, $1/f$ noise and Raman studie...
2109.00504v2
2021-10-05
Carrier transport and performance limit of semi-transparent photovoltaics: CuIn$_{1-x}$Ga$_x$Se$_2$ as a case study
Semi-transparent photovoltaic devices for building integrated applications have the potential to provide simultaneous power generation and natural light penetration. CuIn$_{1-x}$Ga$_x$Se$_2$ (CIGS) has been established as a mature technology for thin-film photovoltaics, however, its potential for Semi-Transparent Photo...
2110.02146v1
2022-01-11
Spectral Thermal Spreading Resistance of Wide Bandgap Semiconductors in Ballistic-Diffusive Regime
To develop efficient thermal management strategies for wide bandgap (WBG) semiconductor devices, it is essential to have a clear understanding of the heat transport process within the device and accurately predict the junction temperature. In this paper, we used the phonon Monte Carlo (MC) method with the phonon disper...
2201.03788v1
2022-03-23
Improved Gradual Resistive Switching Range and 1000x On/Off Ratio in HfOx RRAM Achieved with a $Ge_2Sb_2Te_5$ Thermal Barrier
Gradual switching between multiple resistance levels is desirable for analog in-memory computing using resistive random-access memory (RRAM). However, the filamentary switching of $HfO_x$-based conventional RRAM often yields only two stable memory states instead of gradual switching between multiple resistance states. ...
2203.12190v1
2022-05-09
Reconciling scaling of the optical conductivity of cuprate superconductors with Planckian resistivity and specific heat
Materials tuned to a quantum critical point display universal scaling properties as a function of temperature $T$ and frequency $\omega$. A long-standing puzzle regarding cuprate superconductors has been the observed power-law dependence of optical conductivity with an exponent smaller than one, in contrast to $T$-line...
2205.04030v2
2022-05-23
Electrical Resistivity of Polycrystalline Graphene: Effect of Grain-Boundary-Induced Strain Fields
We have revealed the decisive role of grain-boundary-induced strain fields in electron scattering in polycrystalline graphene. To this end, we have formulated the model based on Boltzmann transport theory which properly takes into account the microscopic structure of grain boundaries (GB) as a repeated sequence of hept...
2205.11270v1
2022-05-31
Anisotropic signatures of the electronic correlations in the electrical resistivity of UTe$_2$
Multiple unconventional superconducting phases are suspected to be driven by magnetic fluctuations in the heavy-fermion paramagnet UTe$_2$, and a challenge is to identify the signatures of the electronic correlations, including the magnetic fluctuations, in the bulk physical quantities. Here, we investigate thoroughly ...
2205.15789v2
2022-06-11
On the Fermi gas, the Sommerfeld fine structure constant, and the electron-electron scattering in conductors
Electrical energy is considered as a fundamental parameter for inclusion in Fermi gas theory, in addition to thermal energy. It is argued that electrical energy can move some electrons to above the Fermi Level, providing free charges to carry the electrical current, even at absolute zero temperature. The Drude model, O...
2206.05393v2
2022-06-30
Antipolar transitions in GaNb$_4$Se$_8$ and GaTa$_4$Se$_8$
We present dielectric, polarization, resistivity, specific heat, and magnetic susceptibility data on single crystals of the lacunar spinels GaNb4Se8 and GaTa4Se8, tetrahedral cluster-based materials with substantial spin-orbit coupling. We concentrate on the possible occurrence of antipolar order in these compounds, as...
2206.15200v2
2022-11-16
Decoupling the Roles of Defects/Impurities and Wrinkles in Thermal Conductivity of Wafer-scale hBN Films
We demonstrate a non-monotonic evolution of thermal conductivity of large-area hexagonal boron nitride films with thickness. Wrinkles and defects/impurities are present in these films. Raman spectroscopy, an optothermal non-contact technique, is employed to probe the temperature and laser power dependence property of t...
2211.08683v2
2022-11-18
Magnetotransport induced by anomalous Hall effect
In a magnetic metal, the Hall resistance is generally taken to be the sum of the ordinary Hall resistance and the anomalous Hall resistance. Here it is shown that this empirical relation is no longer valid when either the ordinary Hall angle or the anomalous Hall angle is not small. Using the proper conductivity relati...
2211.10222v2
2022-12-08
Theory of the Little-Parks effect in spin-triplet superconductors
The celebrated Little-Parks effect in mesoscopic superconducting rings has recently gained great attention due to its potential to probe half-quantum vortices in spin-triplet superconductors. However, despite the large number of works reporting anomalous Little-Parks measurements attributed to unconventional supercondu...
2212.04591v1
2023-04-16
Anomalous and Topological Hall Resistivity in Ta/CoFeB/MgO Magnetic Systems for Neuromorphic Computing Applications
Topologically protected spin textures, such as magnetic skyrmions, have the potential for dense data storage as well as energy-efficient computing due to their small size and a low driving current. The evaluation of the writing and reading of the skyrmion's magnetic and electrical characteristics is a key step toward t...
2304.07742v1
2023-09-01
Multilayer Ferromagnetic Spintronic Devices for Neuromorphic Computing Applications
Spintronics has gone through substantial progress due to its applications in energy-efficient memory, logic and unconventional computing paradigms. Multilayer ferromagnetic thin films are extensively studied for understanding the domain wall and skyrmion dynamics. However, most of these studies are confined to the mate...
2309.00476v1
2024-01-30
Effect of the Sc/Zr ratio on the corrosion resistance of Al-Mg cast alloys
The results of investigations of the corrosion resistance of Al-Mg-Sc-Zr alloys with varying Mg content and different Sc/Zr ratios are presented. The objects of investigations were the Al-Mg-Sc-Zr alloys with total Sc + Zr content of 0.32 wt%. The concentration of Sc and Zr in the alloys varied with the increments of 0...
2401.17429v1
1997-02-27
High temperature anomaly of the conductance of a tunnel junction
The linear conductance of a tunnel junction in series with an ohmic resistor is determined in the high temperature limit. The tunneling current is treated nonperturbatively by means of path integral techniques. Due to quantum effects the conductance is smaller than the classical series conductance. The reduction factor...
9702242v3
2002-10-11
High-field side of Superconductor-Insulator Transition
We report the experimental observation of a magnetic-field-tuned superconductor-insulator transition (SIT) in ultrathin TiN films. The low temperature transport properties of these films show scaling behavior consistent with a transition driven by quantum phase fluctuations in two-dimensional superconductor. The magnet...
0210250v1
2003-11-11
Nonlocal effects in high energy charged particle beams
Within the framework of the thermal wave model, an investigation is made of the longitudinal dynamics of high energy charged particle beams. The model includes the self-consistent interaction between the beam and its surroundings in terms of a nonlinear coupling impedance, and when resistive as well as reactive parts a...
0311139v1
2008-11-05
High-pressure, transport, and thermodynamic properties of CeTe3
We have performed high-pressure, electrical resistivity, and specific heat measurements on CeTe3 single crystals. Two magnetic phases with nonparallel magnetic easy axes were detected in electrical resistivity and specific heat at low temperatures. We also observed the emergence of an additional phase at high pressures...
0811.0792v2
2009-07-30
High order fractional microwave induced resistance oscillations in 2D systems
We report on the observation of microwave-induced resistance oscillations associated with the fractional ratio n/m of the microwave irradiation frequency to the cyclotron frequency for m up to 8 in a two-dimensional electron system with high electron density. The features are quenched at high microwave frequencies inde...
0907.5315v1
2010-11-24
A spark-resistant bulk-micromegas chamber for high-rate applications
We report on the design and performance of a spark-resistant bulk-micromegas chamber. The principle of this design lends itself to the construction of large-area muon chambers for the upgrade of the detectors at the Large Hadron Collider at CERN for luminosities in excess of 10**34/cm2/s or other high-rate applications...
1011.5370v1
2012-12-10
Quantized escape and formation of edge channels at high Landau levels
We present nonlocal resistance measurements in an ultra high mobility two dimensional electron gas. Our experiments show that even at weak magnetic fields classical guiding along edges leads to a strong non local resistance on macroscopic distances. In this high Landau level regime the transport along edges is dissipat...
1212.2026v1
2019-06-26
Studies on small charge packet transport in high-resistivity fully-depleted CCDs
In this work, we will present a physical model and measurements of the transport of small charge packets in the bulk of thick high resistivity CCD before being collected by the pixel potential wells. A new technique to measure the lateral spread of the charge as a function of the ionization depth in the bulk is present...
1906.11379v1
2011-07-09
Resistance to TB drugs in KwaZulu-Natal: causes and prospects for control
In 2005 there was an outbreak of XDR (extensively drug resistant) TB in Tugela Ferry, which is served by the Church of Scotland Hospital (COSH), in the uMzinyathi District, KwaZulu-Natal, South Africa. An investigation was carried out to determine if XDR TB was occurring elsewhere in the province, and to develop hypoth...
1107.1800v1
2012-02-06
Performances of Anode-resistive Micromegas for HL-LHC
Micromegas technology is a promising candidate to replace Atlas forward muon chambers -tracking and trigger- for future HL-LHC upgrade of the experiment. The increase on background and pile-up event probability requires detector performances which are currently under studies in intensive RD activities. We studied per...
1202.1074v1
2018-11-12
Phonon-induced giant linear-in-$T$ resistivity in magic angle twisted bilayer graphene: Ordinary strangeness and exotic superconductivity
We study the effect of electron-acoustic phonon interactions in twisted bilayer graphene on resistivity in the high-temperature transport and superconductivity in the low-temperature phase diagram. We theoretically show that twisted bilayer graphene should have an enhanced and strongly twist-angle dependent linear-in-t...
1811.04920v4
2017-03-07
A Strange Metal from Gutzwiller correlations in infinite dimensions
Recent progress in extremely correlated Fermi liquid theory (ECFL) and dynamical mean field theory (DMFT) enables us to compute in the $d \to \infty$ limit the resistivity of the $t-J$ model after setting $J\to0$. This is also the $U=\infty$ Hubbard model. We study three densities $n=.75,.8,.85$ that correspond to a ra...
1703.02206v3
2019-07-16
General relativistic resistive magnetohydrodynamics with robust primitive variable recovery for accretion disk simulations
Recent advances in black hole astrophysics, particularly the first visual evidence of a supermassive black hole at the center of the galaxy M87 by the Event Horizon Telescope (EHT), and the detection of an orbiting "hot spot" nearby the event horizon of Sgr A* in the Galactic center by the Gravity Collaboration, requir...
1907.07197v2
2020-06-23
Thermal interfacial resistance and nanolayer effect on the thermal conductivity of Al2O3-CO2 nanofluid: A Molecular Dynamics approach
Nanofluids are known to have significantly different thermal properties relative to the corresponding conventional fluids. Heat transfer at the solid-fluid interface affects the thermal properties of nanofluids. The current work helps in understanding the role of two nanoscale phenomena, namely ordering of fluid layer ...
2006.12805v2
2022-03-12
Parameterization of hydrodynamic friction in a model for sheared suspensions of rough particles
We propose a method to parameterize a coarse grained model for the hydrodynamic friction between nearly touching rough spheres in suspension flows. The frictional resistance due to surface roughness primarily alters the sliding and rolling modes of motion of rough particles. Stokesian dynamics simulations incorporating...
2203.06300v1
2003-11-17
Collapse of Magnetized Singular Isothermal Toroids: I. Non-Rotating Case
We study numerically the collapse of non-rotating, self-gravitating, magnetized, singular isothermal toroids characterized by sound speed, $a$, and level of magnetic to thermal support, $H_0$. In qualitative agreement with previous treatments by Galli & Shu and other workers, we find that the infalling material is defl...
0311376v1
2006-02-01
From Protoplanets to Protolife: The Emergence and Maintenance of Life
Despite great advances in our understanding of the formation of the Solar System, the evolution of the Earth, and the chemical basis for life, we are not much closer than the ancient Greeks to an answer of whether life has arisen and persisted on any other planet. The origin of life as a planetary phenomenon will proba...
0602008v1
2000-05-10
Magnetic, thermal, and transport properties on single crystals of antiferromagnetic Kondo-lattice Ce2PdSi3
Magnetization, heat capacity, electrical resistivity, thermoelectric power, and Hall effect have been investigated on single-crystalline Ce_2PdSi_3. This compound is shown to order antiferromagnetically below N'eel temperature (T_N) \~3 K. The Sommerfeld coefficient far below T_N is found to be about 110 mJ/K^2 mol Ce,...
0005164v1
2001-06-03
Transport processes in metal-insulator granular layers
The non-equilibrium tunnel transport processes are considered in a square lattice of metallic nanogranules embedded into insulating host. Based on a simple model with three possible charging states (+,-, or 0) of a granule and three kinetic processes (creation or recombination of a +- pair, and charge transfer) between...
0106034v2
2002-03-06
Concentration Dependence of Superconductivity and Order-Disorder Transition in the Hexagonal Rubidium Tungsten Bronze RbxWO3. Interfacial and bulk properties
We revisited the problem of the stability of the superconducting state in RbxWO3 and identified the main causes of the contradictory data previously published. We have shown that the ordering of the Rb vacancies in the nonstoichiometric compounds have a major detrimental effect on the superconducting temperature Tc.The...
0203120v1
2003-04-19
Transport properties of granular metals at low temperatures
We investigate transport in a granular metallic system at large tunneling conductance between the grains, $g_T\gg 1$. We show that at low temperatures, $T\leq g_T\delta $, where $\delta$ is the single mean energy level spacing in a grain, the coherent electron motion at large distances dominates the physics, contrary t...
0304448v1
2004-03-31
Correlation of microwave surface impedance of MgB_2 thin film with material parameters and a temperature niche for microwave applications
Two issues related to the microwave surface impedance Z_s of MgB_2 thin film are discussed in this Letter, both being significant for potential microwave applications. At first, a correlation between Zs and Alpha = Xi/l was found, where Xi is the coherence length, and l is the mean free path. The surface resistance Rs ...
0403755v1
2004-10-21
Effect of nanometer-sized B powder on phase formation of polycrystalline MgB2
The size effect of the raw B powder on the MgB2 phase formation has been studied by the technique of in-situ high temperature resistivity (HT-rT) measurement. The onset temperature, Tonset, and the completion temperature, TPF, of the phase formation are determined directly during the ongoing thermal process. These two ...
0410533v1
2005-03-18
Aharonov-Bohm electron interferometer in the integer quantum Hall regime
We report experiments on a quantum electron interferometer fabricated from high mobility, low density GaAs/AlGaAs heterostructure material. In this device, a nearly circular electron island is defined by four front gates deposited in etched trenches. The island is separated from the 2D electron bulk by two nearly open ...
0503456v2
2006-09-05
Electrical and Thermal Transport in Metallic Single-Wall Carbon Nanotubes on Insulating Substrates
We analyze transport in metallic single-wall carbon nanotubes (SWNTs) on insulating substrates over the bias range up to electrical breakdown in air. To account for Joule self-heating, a temperature-dependent Landauer model for electrical transport is coupled with the heat conduction equation along the nanotube. The el...
0609075v2
2009-09-14
Progress in the development of a S RETGEM-based detector for an early forest fire warning system
In this paper we present a prototype of a Strip Resistive Thick GEM photosensitive gaseous detector filled with Ne and ethylferrocene vapours at a total pressure of 1 atm for an early forest fire detection system. Tests show that it is one hundred times more sensitive than the best commercial ultraviolet flame detector...
0909.2480v1
2009-09-28
Hall effect in superconducting Fe(Se0.5Te0.5) thin films
The Hall effect is investigated for eight superconducting Fe(Se_0.5_Te_0.5_) thin films grown on MgO and LaSrAlO_4_ substrates with different transition temperatures (T_c_). The normal Hall coefficients (R_H_) have positive values with magnitude of 1 - 1.5 x 10^-3^ cm^3^/C at room temperature for the all samples. With ...
0909.4985v3
2010-11-14
Tunneling anisotropic magnetoresistance of NiFe/IrMn/MgO/Pt stack: An antiferromagnet based spin-valve
Spin-valve is a microelectronic device in which high and low resistance states are realized by utilizing both charge and spin of carriers. Spin-valve structures used in modern hard drive read-heads and magnetic random access memories comprise two ferromagnetic (FM) electrodes whose relative magnetization orientations c...
1011.3188v1
2011-09-09
Study of ageing in Al-Mg-Si alloys by positron annihilation spectroscopy
In many common Al-Mg-Si alloys (6000 series) intermediate storage at or near 'room temperature' after solutionising leads to pronounced changes of the precipitation kinetics during the ensuing artificial ageing step at \approx 180{\deg}C. This is not only an annoyance in production, but also a challenge for researchers...
1109.2019v2
2012-11-20
Enhanced superconducting performance of melt quenched Bi2Sr2CaCu2O8 (Bi-2212) superconductor
We scrutinize the enhanced superconducting performance of melt quench Bismuth based Bi2Sr2CaCu2O8 (Bi-2212) superconductor. The superconducting properties of melt quenched Bi-2212 (Bi2212-MQ) sample are compared with non-melted Bi2212-NM and Bi1.4Pb0.6Sr2Ca2Cu3O10 (Bi-2223). Crystal structure and morphology of the samp...
1211.4681v2
2013-07-27
Strain-induced effects on the magnetic and electronic properties of epitaxial Fe$_{1-x}$Co$_{x}$Si thin films
We have investigated the Co-doping dependence of the structural, transport, and magnetic properties of \epsilon-FeCoSi epilayers grown by molecular beam epitaxy on silicon (111) substrates. Low energy electron diffraction, atomic force microscopy, X-ray diffraction, and high resolution transmission electron microscopy ...
1307.7301v1
2013-08-05
Enhancement of superconductivity near the pressure-induced semiconductor-metal transition in BiS2-based compounds LnO(0.5)F(0.5)BiS2 (Ln = La, Ce, Pr, Nd)
Measurements of electrical resistivity were performed between 3 and 300 K at various pressures up to 2.8 GPa on the BiS2-based superconductors LnO0.5F0.5BiS2 (Ln = Pr, Nd). At lower pressures, PrO0.5F0.5BiS2 and NdO0.5F0.5BiS2 exhibit superconductivity with critical temperatures Tc of 3.5 and3.9 K, respectively. As pre...
1308.1072v3
2014-02-13
Colloidal pattern replication through contact photolithography operated in a "Talbot-Fabry-Perot" regime
We detail on a continuous colloidal pattern replication by using contact photolithography. Chrome on quartz masks are fabricated using colloidal nanosphere lithography and subsequently used as photolithography stamps. Hexagonal pattern arrangements with different dimensions (980, 620 and 480 nm, using colloidal particl...
1402.3117v1
2014-02-28
Exploring of point-contact spectra of Ba1-xNaxFe2As2 in the normal and superconducting state
We present study of derivatives of current-voltage I(V) characteristics of point-contacts (PCs) based on Ba{1-x}Na{x}Fe2As2 (x=0.25) in the normal and superconducting state. The detailed analysis of dV/dI(V) data (also given in Appendix A) shows that the thermal regime, when temperature increases with a voltage at a ra...
1402.7233v1
2014-03-16
Electrical Contacts to Three-Dimensional Arrays of Carbon Nanotubes
We use numerical simulations to investigate the properties of metal contacts to three-dimensional arrays of carbon nanotubes (CNTs). For undoped arrays top-contacted with high or low work function metals, electrostatic screening is very strong, resulting in a small Schottky barrier for current injection in the top laye...
1403.3942v1
2014-06-05
Giant overlap between the magnetic and superconducting phases of CeAu2Si2 under pressure
High pressure provides a powerful means for exploring unconventional superconductivity which appears mostly on the border of magnetism. Here we report the discovery of pressure-induced heavy fermion superconductivity up to 2.5 K in the antiferromanget CeAu2Si2 (TN ~ 10 K). Remarkably, the magnetic and superconducting p...
1406.1438v2
2014-09-10
Proximity effects at the interface of a superconductor and a topological insulator in NbN - Bi_2Se_3 thin film bilayers
In a search for a simple proximity system of a topological insulator and a superconductor for studying the role of surface versus bulk effects by gating, we report here on a first step toward this goal, namely the choice of such a system and its characterization. We chose to work with thin film bilayers of grainy 5 nm ...
1409.2975v1
2015-02-15
Contact doping, Klein tunneling, and asymmetry of shot noise in suspended graphene
The inherent asymmetry of the electric transport in graphene is attributed to Klein tunneling across barriers defined by $\textit{pn}$-interfaces between positively and negatively charged regions. By combining conductance and shot noise experiments we determine the main characteristics of the tunneling barrier (height ...
1502.04330v2
2015-10-06
Spin Hall magnetoresistance as a probe for surface magnetization in Pt/CoFe$_2$O$_4$ bilayers
We study the spin Hall magnetoresistance (SMR) in Pt grown $\textit{in situ}$ on CoFe$_2$O$_4$ (CFO) ferrimagnetic insulating (FMI) films. A careful analysis of the angle-dependent and field-dependent longitudinal magnetoresistance indicates that the SMR contains a contribution that does not follow the bulk magnetizati...
1510.01449v2
2015-11-25
Quantum oscillations of the topological surface states in low carrier concentration crystals of Bi$_{2-x}$Sb$_{x}$Te$_{3-y}$Se$_{y}$
We report a high-field magnetotransport study on selected low-carrier crystals of the topological insulator Bi$_{2-x}$Sb${_x}$Te$_{3-y}$Se$_{y}$. Monochromatic Shubnikov - de Haas (SdH) oscillations are observed at 4.2~K and their two-dimensional nature is confirmed by tilting the magnetic field with respect to the sam...
1511.08186v1
2016-05-06
Antiferromagnetism in trigonal SrMn2As2 and CaMn2As2 single crystals
Crystallographic, electronic transport, thermal and magnetic properties are reported for SrMn2As2 and CaMn2As2 single crystals grown using Sn flux. Rietveld refinements of powder x-ray diffraction data show that the two compounds are isostructural and crystallize in the trigonal CaAl2Si2-type structure (space group P-3...
1605.02052v2
2016-06-13
Observation of Spatial Charge and Spin Correlations in the 2D Fermi-Hubbard Model
Strong electron correlations lie at the origin of transformative phenomena such as colossal magneto-resistance and high-temperature superconductivity. Already near room temperature, doped copper oxide materials display remarkable features such as a pseudo-gap and a "strange metal" phase with unusual transport propertie...
1606.04089v1
2016-06-24
Epitaxial graphene homogeneity and quantum Hall effect in millimeter-scale devices
Quantized magnetotransport is observed in 5.6 x 5.6 mm^2 epitaxial graphene devices, grown using highly constrained sublimation on the Si-face of SiC(0001) at high temperature (1900 {\deg}C). The precise quantized Hall resistance of Rxy = h/2e^2 is maintained up to record level of critical current Ixx = 0.72 mA at T = ...
1606.07720v1
2016-07-11
The electronic thermal conductivity of graphene
Graphene, as a semimetal with the largest known thermal conductivity, is an ideal system to study the interplay between electronic and lattice contributions to thermal transport. While the total electrical and thermal conductivity have been extensively investigated, a detailed first-principles study of its electronic t...
1607.03037v1
2016-07-26
Interface-driven topological Hall effect in SrRuO$_3$-SrIrO$_3$ bilayer
Electron transport coupled with magnetism has attracted attention over the years as exemplified in anomalous Hall effect due to a Berry phase in momentum space. Another type of unconventional Hall effect -- topological Hall effect, originating from the real-space Berry phase, has recently become of great importance in ...
1607.07536v1
2016-08-25
Kelvin probe characterization of buried graphitic microchannels in single-crystal diamond
In this work, we present an investigation by Kelvin Probe Microscopy (KPM) of buried graphitic microchannels fabricated in single-crystal diamond by direct MeV ion microbeam writing. Metal deposition of variable-thickness masks was adopted to implant channels with emerging endpoints and high temperature annealing was p...
1608.07126v1
2016-08-30
Epitaxial thin films of pyrochlore iridate Bi_{2+x}Ir_{2-y}O_{7-delta}: structure, defects and transport properties
While pyrochlore iridate thin films are theoretically predicted to possess a variety of emergent topological properties, experimental verification of these predictions can be obstructed by the challenge in thin film growth. Here we report on the pulsed laser deposition and characterization of thin films of a representa...
1608.08608v3
2017-10-04
Formation, stratification, and mixing of the cores of Earth and Venus
Earth possesses a persistent, internally-generated magnetic field, whereas no trace of a dynamo has been detected on Venus, at present or in the past, although a high surface temperature and recent resurfacing events may have removed paleomagnetic evidence. Whether or not a terrestrial body can sustain an internally ge...
1710.01770v1
2018-03-30
Thermodynamics of Ion Separation by Electrosorption
We present a simple, top-down approach for the calculation of minimum energy consumption of electrosorptive ion separation using variational form of the (Gibbs) free energy. We focus and expand on the case of electrostatic capacitive deionization (CDI), and the theoretical framework is independent of details of the dou...
1803.11532v1
2018-05-22
Non-saturating large magnetoresistance in semimetals
The rapidly expanding class of quantum materials known as {\emph{topological semimetals}} (TSM) display unique transport properties, including a striking dependence of resistivity on applied magnetic field, that are of great interest for both scientific and technological reasons. However, experimental signatures that c...
1805.08797v2