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2020-09-04
Thermal conductivity of PbTe-CoSb3 bulk polycrystalline composite: the role of microstructure and interface thermal resistance
Systematic experimental and theoretical research on the role of microstructure and interface thermal resistance on the thermal conductivity of the PbTe-CoSb3 bulk polycrystalline composite is presented. In particular, the correlation between the particle size of the dispersed phase and interface thermal resistance (R_{...
2009.02190v2
2020-09-20
Development of a computational software in Python, used to study the materials resistance in beams
In this research, we do a software writing in Python to calculate the efforts, bending moments and deformations in beams of different materials. This computational tool, that we developed, is of great help in area of computational physical, more exactly in resistance of materials, which serves as support for researcher...
2009.09448v2
2022-07-01
High-throughput analysis of Fröhlich-type polaron models
The electronic structure of condensed matter can be significantly affected by the electron-phonon interaction, leading to important phenomena such as electrical resistance, superconductivity or the formation of polarons. This interaction is often neglected in band structure calculations but can have a strong impact on ...
2207.00364v1
2013-03-26
Molecular Memory with Atomically-Smooth Graphene Contacts
We report the use of bilayer graphene as an atomically-smooth contact for nanoscale devices. A two-terminal Bucky ball (C60) based molecular memory is fabricated with bilayer graphene as a contact on the polycrystalline nickel electrode. Graphene provides an atomically-smooth covering over an otherwise rough metal surf...
1303.6603v1
2020-04-10
Vortex Dynamics and Dissipation Under High-amplitude Microwave Drive
In this paper, we describe the vortex dynamics under high-amplitude microwave drive and its effect on the surface resistance of superconductors. The vortex surface resistance is calculated with a Montecarlo approach, where the vortex motion equation is solved for a collection of vortex flux lines each oscillating withi...
2004.05083v2
2015-07-17
Resistive thrust production can be as crucial as added mass mechanisms for inertial undulatory swimmers
In this paper, we address a crucial point regarding the description of moderate to high Reynolds numbers aquatic swimmers. For decades, swimming animals have been classified in two different families of propulsive mechanisms based on the Reynolds number: the "resistive" swimmers, using local friction to produce the nec...
1507.04952v1
2022-07-13
Memristive and tunneling effects in 3D interconnected silver nanowires
Due to their memristive properties nanowire networks are very promising for neuromorphic computing applications. Indeed, the resistance of such systems can evolve with the input voltage or current as it confers a synaptic behaviour to the device. Here, we propose a network of silver nanowires (Ag-NWs) which are grown i...
2207.06338v1
2011-05-06
Giant microwave photoresistivity in a high-mobility quantum Hall system
We report the observation of a remarkably strong microwave photoresistivity effect in a high-mobility two-dimensional electron system subject to a weak magnetic field and low temperature. The effect manifests itself as a giant microwave-induced resistivity peak which, in contrast to microwave-induced resistance oscilla...
1105.1390v1
2014-11-19
Towards pristine graphene-metal interface and microstructures: Laser assisted direct patterning on Epitaxial graphene
Graphene-metal contact resistance is governed by both intrinsic and extrinsic factors. Intrinsically, both the density of states bottleneck near the Dirac point and carrier reflection at the graphene-metal interface lead to a high contact resistance. Moreover, graphene exhibits insulating behavior for out-of-the-plane ...
1411.5114v1
2023-11-08
An attention-based deep learning network for predicting Platinum resistance in ovarian cancer
Background: Ovarian cancer is among the three most frequent gynecologic cancers globally. High-grade serous ovarian cancer (HGSOC) is the most common and aggressive histological type. Guided treatment for HGSOC typically involves platinum-based combination chemotherapy, necessitating an assessment of whether the patien...
2311.04769v1
2000-08-17
Development of Gold Contacted Flip-chip Detectors with IMARAD CZT
We present initial results from our evaluation of a gold-contacted pixellated detector using cadmium zinc telluride substrate produced by IMARAD Imaging Systems. The Horizontal Bridgman (HB) grown crystals from IMARAD have been shown to produce high resolution photopeaks, but they are also seen to have large leakage cu...
0008275v1
1997-09-21
Microwave properties of $(Pr_xY_{1-x})Ba_2Cu_3O_{7-δ}$ : Influence of magnetic scattering
We report measurements of the surface impedance $Z_s=R_s+iX_s$ of $(Pr_xY_{1-x})Ba_2Cu_3O_{7-\delta}$, $(x=0,0.15,0.23,0.3,0.4,0.5)$. Increasing $Pr$ concentration leads to some striking results not observed in samples doped by non-magnetic constituents. The three principal features of the $R_s(T)$ data - multiple stru...
9709232v1
1997-12-08
High frequency magneto-electrodynamics of La_(1-x)Sr_xMnO3 single crystals
The radio frequency (RF) response of La1-xSrxMnO3 single crystals reveal a variety of features associated with the structural, electronic and magnetic properties of the system. The resonance technique operating at ~ 4 MHz employed in this study is sensitive to small changes in both the magnetic susceptibility and resis...
9712093v1
1999-04-28
Structure and properties of a novel fulleride Sm6C60
A novel fulleride Sm6C60 has been synthesized using high temperature solid state reaction. The Rietveld refinement on high resolution synchrotron X-ray powder diffraction data shows that Sm6C60 is isostructural with body-centered cubic A6C60 (A=K, Ba). Raman spectrum of Sm6C60 is similar to that of Ba6C60, and the freq...
9904404v1
2000-04-10
Magnetotransport study of the charged stripes in high-T_c cuprates
We present a study of the in-plane and out-of-plane magnetoresistance (MR) in heavily-underdoped, antiferromagnetic YBa_{2}Cu_{3}O_{6+x}, which reveals a variety of striking features. The in-plane MR demonstrates a "d-wave"-like anisotropy upon rotating the magnetic field H within the ab plane. With decreasing temperat...
0004135v1
2000-07-11
Grain boundary effects on magnetotransport in bi-epitaxial films of La$_{0.7}$Sr$_{0.3}$MnO$_3$
The low field magnetotransport of La$_{0.7}$Sr$_{0.3}$MnO$_3$ (LSMO) films grown on SrTiO$_3$ substrates has been investigated. A high qualtity LSMO film exhibits anisotropic magnetoresistance (AMR) and a peak in the magnetoresistance close to the Curie temperature of LSMO. Bi-epitaxial films prepared using a seed laye...
0007194v1
2001-02-23
Temperature Dependence of Low-Lying Electronic Excitations of LaMnO_3
We report on the optical properties of undoped single crystal LaMnO_3, the parent compound of the colossal magneto-resistive manganites. Near-Normal incidence reflectance measurements are reported in the frequency range of 20-50,000 cm-1 and in the temperature range 10-300 K. The optical conductivity, s_1(w), is derive...
0102437v1
2001-02-27
Anisotropic three-dimentional magnetic fluctuations in heavy fermion CeRhIn5
CeRhIn5 is a heavy fermion antiferromagnet that orders at 3.8 K. The observation of pressure-induced superconductivity in CeRhIn5 at a very high Tc of 2.1 K for heavy fermion materials has led to speculations regarding to its magnetic fluctuation spectrum. Using magnetic neutron scattering, we report anisotropic three-...
0102503v1
2001-12-21
First order transition from ferromagnetism to antiferromagnetism in Ce(Fe$_{0.96}$Al$_{0.04}$)$_2$: a magnetotransport study
The magnetotransport behaviour is investigated in detail across the first order magnetic phase transition from ferromagnetic to antiferromagnetic state in polycrystalline Ce(Fe$_{0.96}$Al$_{0.04}$)$_2$ sample. The study clearly brings out various generic features associated with a first order transition, viz., hysteres...
0112408v1
2002-08-07
Transport critical current densities and n factors in mono- and multifilamentary MgB2/Fe tapes and wires using fine powders
Mono- and multifilamentary MgB2/Fe tapes and wires with high transport critical current densities have been prepared using the powder-in-tube (PIT) process. The fabrication details are described. The effect of powder grain sizes and recrystallization temperature on jc has been investigated. At 25K and 1 T, jc values cl...
0208133v1
2004-02-20
Metal-insulator transition and glassy behavior in two-dimensional electron systems
Studies of low-frequency resistance noise demonstrate that glassy freezing occurs in a two-dimensional electron system in silicon in the vicinity of the metal-insulator transition (MIT). The width of the metallic glass phase, which separates the 2D metal and the (glassy) insulator, depends strongly on disorder, becomin...
0402535v1
2004-04-21
Formation and Thermal Stability of sub-10 nm Carbon Templates on Si(100)
We report a lithographic process for creating high-resolution (<10 nm) carbon templates on Si(100). A scanning electron microscope, operating under low vacuum (10E-6 mbar), produces a carbon-containing deposit ("contamination resist") on the silicon surface via electron-stimulated dissociation of ambient hydrocarbons, ...
0404505v1
2005-04-19
High temperature magnetic ordering in La2RuO5
Magnetic susceptibility, heat capacity and electrical resistivity measurements have been carried out on a new ruthenate, La2RuO5 (monoclinic, space group P21/c) which reveal that this compound is a magnetic semiconductor with a high magnetic ordering temperature of 170K. The entropy associated with the magnetic transit...
0504489v1
2006-05-11
Multifilament YBa2Cu3O6+x -coated conductors with minimized coupling losses
We report an experimental approach to making multifilament coated conductors with low losses in applied time-varying magnetic field. Previously, the multifilament conductors obtained for that purpose by laser ablation suffered from high coupling losses. Here we report how this problem can be solved. When the substrate ...
0605313v1
2006-06-17
The thermally activated motion of vortex bundles and the anomalous Hall effect in type-II conventional and high-Tc superconductors
The anomalous Hall effect in type-II conventional and high-Tc superconductors is investigated based on the proposed novel theory of the thermally activated motion of vortex bundles over a directional-dependent energy barrier. Our calculations demonstrate clearly that anomalous Hall effect is induced by the competition ...
0606464v2
1999-11-30
Analysis of trap spectra in LEC and epitaxial GaAs
Different methods of trap parameter measurement are analysed. Transient photoconductivity and thermally stimulated effects were used to investigate the influence of traps in LEC SI-GaAs and high resistivity epitaxial GaAs. The peculiarities of the TSC were analysed and shown to be related to the influence of crystal mi...
9911048v1
2006-08-25
The Effects of Preheating of a Fine Tungsten Wire and the Polarity of a High-Voltage Electrode on the Energy Characteristics of an Electrically Exploded Wire in Vacuum
Results obtained from experimental and numerical studies of tungsten wires electrical explosion in vacuum are presented. The experiments were performed both with and without preheating of the wires, using positive or negative polarity of a high-voltage electrode. Preheating is shown to increase energy deposition in the...
0608251v1
2007-03-11
A low-noise ferrite magnetic shield
Ferrite materials provide magnetic shielding performance similar to commonly used high permeability metals but have lower intrinsic magnetic noise generated by thermal Johnson currents due to their high electrical resistivity. Measurements inside a ferrite shield with a spin-exchange relaxation-free atomic magnetometer...
0703115v2
2007-08-14
The zero-energy state in graphene in a high magnetic field
The fate of the charge-neutral Dirac point in graphene in a high magnetic field $H$ has been investigated at low temperatures ($T\sim$ 0.3 K). In samples with small $V_0$ (the gate voltage needed to access the Dirac point), the resistance $R_0$ at the Dirac point diverges steeply with $H$, signalling a crossover to an ...
0708.1959v2
2008-03-25
Superconductivity at 43 K in Samarium-arsenide Oxides $SmFeAsO_{1-x}F_x$
Since the discovery of high-transition temperature ($T_c$) superconductivity in layered copper oxides, extensive efforts have been devoted to explore the higher $T_c$ superconductivity. However, the $T_c$ higher than 40 K can be obtained only in the copper oxide superconductors so far. The highest reported value of $T_...
0803.3603v2
2008-04-21
CeFePO: A Heavy Fermion Metal with Ferromagnetic Correlations
The ground state properties of CeFePO, a homologue of the new high temperature superconductors RFePnO(1-x)Fx, were studied by means of susceptibility, specific heat, resistivity, and NMR measurements on polycrystals. All the results demonstrate that this compound is a magnetically non-ordered heavy Fermion metal with a...
0804.3250v2
2008-07-05
Growth and characterization of A_{1-x}K_xFe_2As_2 (A = Ba, Sr) single crystals with x=0 - 0.4
Single crystals of A$_{1-x}$K$_x$Fe$_2$As$_2$ (A=Ba, Sr) with high quality have been grown successfully by FeAs self-flux method. The samples have sizes up to 4 mm with flat and shiny surfaces. The X-ray diffraction patterns suggest that they have high crystalline quality and c-axis orientation. The non-superconducting...
0807.0759v3
2008-08-18
A Ni-based Superconductor: the Heusler Compound ZrNi$_2$Ga
This work reports on the novel Heusler superconductor ZrNi2Ga. Compared to other nickel-based superconductors with Heusler structure, ZrNi2Ga exhibits a relatively high superconducting transition temperature of Tc=2.9 K and an upper critical field of 1.5 T. Electronic structure calculations show that this relatively hi...
0808.2356v1
2008-10-03
Small anisotropy, weak thermal fluctuations, and high field superconductivity in Co-doped iron pnictide Ba(Fe1-xCox)2As2
We performed high-field magnetotransport and magnetization measurements on a single crystal of the 122-phase iron pnictide Ba(Fe1-xCox)2As2. Unlike the HTS cuprates and 1111-phase oxypnictides, Ba(Fe1-xCox)2As2 showed practically no broadening of the resistive transitions under magnetic fields up to 45 T. The mass anis...
0810.0699v2
2009-05-01
Highly segmented thin microstrip detector with data-driven fast readout
In September 2008 the Slim5 collaboration submitted a low material budget silicon demonstrator to test with 12 GeV/c protons, at the PS-T9 test-beam at CERN. Inside the reference telescope, two different detectors were placed as device under test (DUT). The first was a 4k-Pixel Matrix of Deep N Well MAPS, developed in ...
0905.0083v3
2009-10-08
Structural and transport properties of Sr2VO{3-delta}FeAs superconductors with different oxygen deficiencies
Sr2VO{3-delta}FeAs superconductors with different oxygen deficiencies have been successfully fabricated. It is found that the superconducting transition temperature drops down monotonically with the increase of oxygen deficiency. The diminishing of superconductivity is accompanied by the enhancement of residual resisti...
0910.1537v2
2010-04-22
Optimizing Transistor Performance of Percolating Carbon Nanotube Networks
In percolating networks of mixed metallic and semiconducting CNTs, there is a tradeoff between high on-current (dense networks) and high on/off ratio (sparse networks in which the metallic CNT fraction is not percolating). Experiments on devices in a transistor configuration and Monte Carlo simulations were performed t...
1004.4009v1
2010-06-25
Spin and charge dynamics in [TbPc$_2$]$^0$ and [DyPc$_2$]$^0$ single molecule magnets
Magnetization, AC susceptibility and $\mu$SR measurements have been performed in neutral phthalocyaninato lanthanide ([LnPc$_2]^0$) single molecule magnets in order to determine the low-energy levels structure and to compare the low-frequency spin excitations probed by means of macroscopic techniques, such as AC suscep...
1006.4919v1
2010-09-17
Graphene Transport at High Carrier Densities using a Polymer Electrolyte Gate
We report the study of graphene devices in Hall-bar geometry, gated with a polymer electrolyte. High densities of 6 $\times 10^{13}/cm^{2}$ are consistently reached, significantly higher than with conventional back-gating. The mobility follows an inverse dependence on density, which can be correlated to a dominant scat...
1009.3367v2
2010-10-28
Poole-Frenkel Effect and Phonon-Assisted Tunneling in GaAs Nanowires
We present electronic transport measurements of GaAs nanowires grown by catalyst-free metal-organic chemical vapor deposition. Despite the nanowires being doped with a relatively high concentration of substitutional impurities, we find them inordinately resistive. By measuring sufficiently high aspect-ratio nanowires i...
1010.6086v1
2010-11-23
NaIrO3 - A pentavalent post-perovskite
Sodium iridium(V) oxide, NaIrO3, was synthesized by a high pressure solid state method and recovered to ambient conditions. It is found to be isostructural with CaIrO3, the much-studied structural analogue of the high-pressure post-perovskite phase of MgSiO3. Among the oxide post-perovskites, NaIrO3 is the first exampl...
1011.5125v2
2010-12-11
Transport Spin Polarization of High-Curie Temperature MnBi Films
We report on the study of the structural, magnetic and transport properties of highly textured MnBi films with the Curie temperature of 628K. In addition to detailed measurements of resistivity and magnetization, we measure transport spin polarization of MnBi by Andreev reflection spectroscopy and perform fully relativ...
1012.2486v1
2011-10-06
High-Precision Tuning of State for Memristive Devices by Adaptable Variation-Tolerant Algorithm
Using memristive properties common for the titanium dioxide thin film devices, we designed a simple write algorithm to tune device conductance at a specific bias point to 1% relative accuracy (which is roughly equivalent to 7-bit precision) within its dynamic range even in the presence of large variations in switching ...
1110.1393v1
2011-10-19
Evaluating the robustness of top coatings comprising plasma-deposited fluorocarbons in electrowetting systems
Thin dielectric stacks comprising a main insulating layer and a hydrophobic top coating are commonly used in low voltage electrowetting systems. However, in most cases, thin dielectrics fail to endure persistent electrowetting testing at high voltages, namely beyond the saturation onset, as electrolysis indicates diele...
1110.4238v1
2011-10-21
P-T phase diagram of iron arsenide superconductor NdFeAsO0.88F0.12
NdFeAsO0.88F0.12 belongs to the recently discovered family of high-TC iron-based superconductors. The influence of high pressure on transport properties of this material has been studied. Contrary to La-based compounds, we did not observe a maximum in TC under pressure. Under compression, TC drops rapidly as a linear f...
1110.4909v1
2011-11-20
Flame Synthesis of Graphene Films in Open Environments
Few-layer graphene (FLG) is grown on copper and nickel substrates at high rates using a novel flame synthesis method in open-atmosphere environments. Transmittance and resistance properties of the transferred films are similar to those grown by other methods, but the concentration of oxygen, as assessed by XPS, is actu...
1111.4699v1
2012-07-25
Conductivity crossover in nano-crystalline diamond films: Realization of a disordered superlattice-like structure
We present the electrical transport characteristics of a batch of nano-crystalline diamond films of varying nitrogen concentrations and explain the conduction mechanism by the disordered quasi-superlattice model applied to semiconductor heterostructures. Synthesized by the hot filament chemical vapour deposition techni...
1207.5916v1
2012-10-23
Impact of the various spin and orbital ordering processes on multiferroic properties of orthovanadate DyVO3
The orthovanadate DyVO3 crystal, known to exhibit multiple structural, spin and orbital ordering transitions, is presently investigated on the basis of magnetization, heat capacity, resistivity, dielectric and polarization measurements. Our main result is experimental evidence for the existence of multiferroicity below...
1210.6373v3
2013-04-04
Atomic Calligraphy: The Direct Writing of Nanoscale Structures using MEMS
We present a micro-electromechanical system (MEMS) based method for the resist free patterning of nano-structures. Using a focused ion beam (FIB) to customize larger MEMS machines, we fabricate apertures as small as 50 nm on plates that can be moved with nanometer precision over an area greater than 20x20 {\mu}m^2. Dep...
1304.1334v1
2013-04-04
Substrate-Independent Catalyst-Free Synthesis of High-Purity Bi2Se3 Nanostructures
We describe a catalyst-free vapor-solid synthesis of bismuth selenide (Bi2Se3) nanostructures at ambient pressure with hydrogen as a carrier gas. The nanostructures were synthesized on glass, silicon and mica substrates and the method yields a variety of nanostructures: nanowires, nanoribbons, nanoplatelets and nanofla...
1304.1388v1
2013-07-14
Voltage-triggered Ultra-fast Metal-insulator Transition in Vanadium Dioxide Switches
Electrically driven metal-insulator transition in vanadium dioxide (VO2) is of interest in emerging memory devices, neural computation, and high speed electronics. We report on the fabrication of out-of-plane VO2 metal-insulator-metal (MIM) structures and reproducible high-speed switching measurements in these two-term...
1307.3774v1
2013-07-17
Dielectric Coatings for IACT Mirrors
Imaging Atmospheric Cherenkov Telescopes for very-high energy gamma-ray astronomy need mirror with high reflectance roughly in the wavelength between 300 and 550 nm. The current standard reflective layer of such mirrors is aluminum. Being permanently exposed to the environment they show a constant degradation over the ...
1307.4557v1
2013-08-14
Perspectives of Micro-Pattern Gaseous Detector Technologies for Future Physics Projects
A centenary after the invention of the basic principle of gas amplification, gaseous detectors - are still the first choice whenever the large area coverage with low material budget is required. Advances in photo-lithography and micro-processing techniques in the chip industry during the past two decades triggered a ma...
1308.3047v2
2013-08-18
Pulsed Laser Deposition of High-Quality Thin Films of the Insulating Ferromagnet EuS
High-quality thin films of the ferromagnetic-insulator europium(II) sulfide (EuS) were fabricated by pulsed laser deposition on Al2O3 (0001) and Si (100) substrates. A single orientation was obtained with the [100] planes parallel to the substrates, with atomic-scale smoothness indicates a near-ideal surface topography...
1308.3820v2
2014-02-19
Monte Carlo Simulation of RPC-based PET with GEANT4
The Resistive Plate Chambers (RPC) are low-cost charged-particle detectors with good timing resolution and potentially good spatial resolution. Using RPC as gamma detector provides an opportunity for application in positron emission tomography (PET). In this work, we use GEANT4 simulation package to study various metho...
1402.4544v1
2014-03-04
Molecular weight dependent bimolecular recombination in organic solar cells
Charge carrier recombination is studied in operational organic solar cells made from the polymer:fullerene system PCDTBT:PC71BM (poly[N-9"-heptadecanyl-2,7-carbazole-alt-5,5-(4',7'-di-2-thienyl-2',1',3'-benzothiadiazole)] : [6,6]-phenyl-C$_{70}$-butyric acid methyl ester). A newly developed technique High Intensity Res...
1403.0972v2
2015-01-27
Transition from semiconducting to metallic-like conducting and weak antilocalization effect in single crystals of LuPtSb
High quality half-Heusler single crystals of LuPtSb have been synthesized by a Pb flux method. The temperature dependent resistivity and Hall effects indicate that the LuPtSb crystal is a p-type gapless semiconductor showing a transition from semiconducting to metallic conducting at 150 K. Moreover, a weakly temperatur...
1501.06714v1
2015-05-22
Synthesis of monoclinic IrTe2 under high pressure and its physical properties
In a pressure-temperature (P-T) diagram for synthesizing IrTe2 compounds, the well-studied trigonal (H) phase with the CdI2-type structure is stable at low pressures. The superconducting cubic (C) phase can be synthesized under higher temperatures and pressures. A rhombohedral phase with the crystal structure similar t...
1505.06124v1
2015-08-12
Direct Observation of Re-entrant Multiferroic CuO at High Pressures
We have carried out a detailed experimental investigation on CuO using dielectric constant, ac resistance, Raman spectroscopy and X-ray diffraction measurements at high pressures and room temperature. Both dielectric constant and dielectric loss show an anomalous peak in the pressure range 3.4-4 GPa indicating a ferroe...
1508.02874v1
2015-10-21
Titanium Nitride as a Seed Layer for Heusler Compounds
Titanium nitride (TiN) shows low resistivity at room temperature, high thermal stability and thus has the potential to serve as seed layer in magnetic tunnel junctions. High quality TiN thin films with regard to the crystallographic and electrical properties were grown and characterized by X-ray diffraction and 4-termi...
1510.06256v3
2016-04-19
Insulating and metallic spin glass in K$_{x}$Fe$_{2-δ-y}$Ni$_{y}$Se$_{2}$ (0.06 $\leq$ $y$ $\leq$ 1.44) single crystals
We report electron doping effects by Ni in K$_{x}$Fe$_{2-\delta-y}$Ni$_{y}$Se$_{2}$ (0.06 $\leq$ $y$ $\leq$ 1.44) single crystal alloys. A rich ground state phase diagram is observed. Small amount of Ni ($\sim$ 4\%) suppressed superconductivity below 1.8 K, inducing insulating spin glass magnetic ground state for highe...
1604.05713v1
2016-05-16
Growth and characterization of CaFe$_{1-x}$Co$_x$AsF single crystals by CaAs flux method
Millimeter sized single crystals of CaFe$_{1-x}$Co$_x$AsF were grown using a self-flux method. It is found that high-quality single crystals can be grown from three approaches with different initial raw materials. The chemical compositions and crystal structure were characterized carefully. The c-axis lattice constant ...
1605.04642v1
2016-06-02
High Current Density 2D/3D Esaki Tunnel Diodes
The integration of two-dimensional materials such as transition metal dichalcogenides with bulk semiconductors offer interesting opportunities for 2D/3D heterojunction-based novel device structures without any constraints of lattice matching. By exploiting the favorable band alignment at the GaN/MoS2 heterojunction, an...
1606.00509v1
2016-06-24
Thermal insulator transition induced by interface scattering
We develop an effective medium model of thermal conductivity that accounts for both percolation and interface scattering. This model accurately explains the measured increase and decrease of thermal conductivity with loading in composites dominated by percolation and interface scattering, respectively. Our model furthe...
1606.07851v2
2016-06-29
Large linear magnetoresistance from neutral defects in Bi$_2$Se$_3$
The chalcogenide Bi$_2$Se$_3$ can attain the three dimensional (3D) Dirac semimetal state under the influence of strain and microstrain. Here we report the presnece of large linear magnetoresistance in such a Bi$_2$Se$_3$ crystal. The magnetoresistance has quadratic form at low fields which crossovers to linear above 4...
1606.09059v1
2016-10-03
Thallium under extreme compression
We present a combined theoretical and experimental study of the high-pressure behavior of thallium. X-ray diffraction experiments have been carried out at room temperature up to 125 GPa using diamond-anvil cells, nearly doubling the pressure range of previous experiments. We have confirmed the hcp-fcc transition at 3.5...
1610.00435v1
2016-10-19
Applications and non-idealities of submicron Al-AlOx-Nb tunnel junctions
We have developed a technique to fabricate sub-micron, 0.6 um x 0.6 um Al-AlOx-Nb tunnel junctions using a standard e-beam resist, angle evaporation and double oxidation of the tunneling barrier, resulting in high quality niobium, as determined by the the high measured values of the critical temperature TC 7.5 K and th...
1610.05903v1
2017-06-28
Super-Hydrophobic Stearic Acid Layer Formed on Anodized High Purified Magnesium for Improving Corrosion Resistance of Biodegradable Implants
Magnesium and its alloys are ideal candidates for biodegradable implants. However, they can dissolve too rapidly in the human body for most applications. In this research, high purified magnesium (HP-Mg) was coated with stearic acid in order to slow the corrosion rate of magnesium in simulated body fluid at 37{\deg}C. ...
1706.09508v1
2017-10-19
Design of high-strength refractory complex solid-solution alloys
Nickel-based superalloys and near-equiatomic high-entropy alloys containing Molybdenum are known for higher temperature strength and corrosion resistance. Yet, complex solid-solution alloys offer a huge design space to tune for optimal properties at slightly reduced entropy. For refractory Mo-W-Ta-Ti-Zr, we showcase KK...
1710.06983v2
2017-11-16
Superconductivity at 7.3 K in the 133-type Cr-based RbCr3As3 single crystals
Here we report the preparation and superconductivity of the 133-type Cr-based quasi-one-dimensional (Q1D) RbCr3As3 single crystals. The samples were prepared by the deintercalation of Rb+ ions from the 233-type Rb2Cr3As3 crystals which were grown from a high-temperature solution growth method. The RbCr3As3 compound cry...
1711.06133v1
2017-12-01
Radiation damage and thermal shock response of carbon-fiber-reinforced materials to intense high-energy proton beams
A comprehensive study on the effects of energetic protons on carbon-fiber composites and compounds under consideration for use as low-Z pion production targets in future high-power accelerators and low-impedance collimating elements for intercepting TeV-level protons at the Large Hadron Collider has been undertaken add...
1712.00509v1
2018-01-08
Automated Instrumentation for the Determination of the High-Temperature Thermoelectric Figure-of-Merit
In this work, we report the fabrication of a high temperature measurement setup to measure Figure of merit (ZT). This setup facilitates the simultaneous measurement of Seebeck coefficient ({\alpha}), thermal conductivity (\kappa), and electrical resistivity (\rho) required to calculate ZT. Measurement of temperature, a...
1801.02360v1
2018-01-30
Structural and electronic phase transitions in FePS$_3$ under the application of pressure
Two-dimensional materials have proven to be a prolific breeding ground of new and unstudied forms of magnetism and unusual metallic states, particularly when tuned between their insulating and metallic phases. In this paper we present work on a new metal to insulator transition system FePS$_3$ . This compound is a two-...
1801.10089v2
2018-03-14
A 1.6:1 Bandwidth Two-Layer Antireflection Structure for Silicon Matched to the 190-310 GHz Atmospheric Window
Although high-resistivity, low-loss silicon is an excellent material for THz transmission optics, its high refractive index necessitates antireflection treatment. We fabricated a wide-bandwidth, two-layer antireflection treatment by cutting subwavelength structures into the silicon surface using multi-depth deep reacti...
1803.05168v2
2018-04-26
Large effective mass and interaction-enhanced Zeeman splitting of $K$-valley electrons in MoSe$_2$
We study the magnetotransport of high-mobility electrons in monolayer and bilayer MoSe$_2$, which show Shubnikov-de Haas (SdH) oscillations and quantum Hall states in high magnetic fields. An electron effective mass of 0.8$m_e$ is extracted from the SdH oscillations' temperature dependence; $m_e$ is the bare electron m...
1804.10104v2
2018-05-31
Unusual magnetotransport in holmium monoantimonide
We report the magnetotransport properties of HoSb, a semimetal with antiferromagnetic ground state. HoSb shows extremely large magnetoresistance (XMR) and Shubnikov-de Haas (SdH) oscillation at low temperature and high magnetic field. Different from previous reports in other rare earth monopnictides, kinks in $\rho(B)$...
1805.12496v1
2018-06-28
Tribological Properties of Ultrananocrystalline Diamond Nanowire Thin Film: Influence of Sliding Ball Counterbodies
Ultrananocrystalline Diamond Nanowire (UNCD NW) thin film was deposited on mirror polished silicon substrate (100) using Microwave Plasma Enhanced Chemical Vapor Deposition (MPECVD) System with optimized deposition parameters in CH4 (6%)/N2 plasma media. The film exhibited wire like morphology with randomly oriented an...
1806.10765v1
2018-09-13
Anisotropic hybridization in a new Kondo lattice compound CeCoInGa$_3$
We report a detailed and comparative study of the single crystal CeCoInGa$_3$ in both experiment and theory. Resistivity measurements reveal the typical behavior of Kondo lattice with the onset temperature of coherence, $T^*\approx 50\,$K. The magnetic specific heat can be well fitted using a spin-fluctuation model at ...
1809.04735v1
2018-11-18
In situ high-cycle fatigue reveals the importance of grain boundary structure in nanocrystalline Cu-Zr
Nanocrystalline metals typically have high fatigue strengths, but low resistance to crack propagation. Amorphous intergranular films are disordered grain boundary complexions that have been shown to delay crack nucleation and slow crack propagation during monotonic loading by diffusing grain boundary strain concentrati...
1811.07263v1
2019-09-02
Thermoelastic equation of state and melting of Mg metal at high pressure and high temperature
The p-V-T equation of state of magnesium metal has been measured up to 20 GPa and 1500 K using both multianvil and opposite anvil techniques combined with synchrotron X-ray diffraction. To fit the experimental data, the model of Anderson-Gr\"uneisen has been used with fixed parameter {\delta}T. The 300-K bulk modulus o...
1909.00645v1
2014-08-28
Crossover of conduction mechanism in Sr2IrO4 epitaxial thin films
High quality epitaxial Sr2IrO4 thin films with various thicknesses (9-300 nm) have been grown on SrTiO3 (001) substrates, and their electric transport properties have been investigated. All samples showed the expected insulating behavior with a strong resistivity dependence on film thickness, that can be as large as th...
1408.6798v1
2017-03-01
Tunnel-injected sub-260 nm ultraviolet light emitting diodes
We report on tunnel-injected deep ultraviolet light emitting diodes (UV LEDs) configured with a polarization engineered Al0.75Ga0.25N/ In0.2Ga0.8N tunnel junction structure. Tunnel-injected UV LED structure enables n-type contacts for both bottom and top contact layers. However, achieving Ohmic contact to wide bandgap ...
1703.00117v1
2019-02-27
High-performance dendritic metamaterial absorber for broadband and near-meter wave radar
Absorbing materials in ultra-high frequency (UHF) band has constantly been a major challenge. The size of the absorber in UHF band is large, whereas the resonant frequency band is narrow. According to Rozanov's theory, two kinds of composite metamaterial absorbers are designed to realize the requirements of low-frequen...
1902.10398v1
2019-07-29
Mechanical Characterisation of the Protective Al$_2$O$_3$ Scale in Cr$_2$AlC MAX phases
MAX phases have great potential under demands of both high-temperature and high-stress performance, with their mixed atomic bonding producing the temperature and oxidation resistance of ceramics with the mechanical resilience of metals. Here, we measure the mechanical properties up to 980C by nanoindentation on highly ...
1907.12341v1
2019-03-21
Stabilization and heteroepitaxial growth of metastable tetragonal FeS thin films by pulsed laser deposition
Pulsed laser deposition, a non-equilibrium thin-film growth technique, was used to stabilize metastable tetragonal iron sulfide (FeS), the bulk state of which is known as a superconductor with a critical temperature of 4 K. Comprehensive experiments revealed four important factors to stabilize tetragonal FeS epitaxial ...
1903.08820v1
2019-03-26
Gate tunable quantum Hall effects in defect-suppressed Bi2Se3 films
Despite many years of efforts, attempts to reach the quantum regime of topological surface states (TSS) on an electrically tunable topological insulator (TI) platform have so far failed on binary TI compounds such as Bi2Se3 due to high density of interfacial defects. Here, utilizing an optimal buffer layer on a gatable...
1903.10945v2
2019-04-09
Alloy Design for Mechanical Properties: Conquering the Length Scales
Predicting the structural response of advanced multiphase alloys and understanding the underlying microscopic mechanisms that are responsible for it are two critically important roles modeling plays in alloy development. An alloys demonstration of superior properties, such as high strength, creep resistance, high ducti...
1904.04569v1
2019-08-13
Investigating the real-time dissolution of a compositionally complex alloy using inline ICP and correlation with XPS
The real-time dissolution of the single-phase compositionally complex alloy (CCA), Al1.5TiVCr, was studied using an inline inductively coupled plasma method. Compositionally complex alloys (CCAs), a term encompassing high entropy alloys (HEAs) or multi-principal element alloys (MPEAs), are - in general - noted for thei...
1908.04493v1
2012-06-01
Quantum Superinductor with Tunable Non-Linearity
We report on the realization of a superinductor, a dissipationless element whose microwave impedance greatly exceeds the resistance quantum. The design of the superinductor, implemented as a ladder of nanoscale Josephson junctions, enables tuning of the inductance and its nonlinearity by a weak magnetic field. The Rabi...
1206.0307v2
2015-07-10
Antibunched photons from inelastic Cooper-pair tunneling
We demonstrate theoretically that charge transport across a Josephson junction, voltage-biased through a resistive environment, produces antibunched photons. We develop a continuous-mode description of the emitted radiation field in a semi-infinite transmission line terminated by the Josephson junction. Within a pertur...
1507.02885v1
2018-07-20
High-Pressure Phase Diagram of NdFeAsO$_{0.9}$F$_{0.1}$: Disappearance of superconductivity on the verge of ferromagnetism from nd moments
We investigated transport and magnetic properties of NdFeAsO$_{0.9}$F$_{0.1}$ single crystal under hydrostatic pressures up to 50\,GPa. The ambient pressure superconductivity at $T_{c} \sim$ 45.4\,K is fully suppressed at $P_{c} \sim$ 21 GPa. Upon further increase of the pressure, the ferromagnetism associated with the...
1807.07729v1
2018-12-19
Benchmarking vdW-DF first principle predictions against Coupled Electron-Ion Monte Carlo for high pressure liquid hydrogen
We report first principle results for nuclear structure and optical responses of high pressure liquid hydrogen along two isotherms in the region of molecular dissociation. We employ Density Functional Theory with the vdW-DF approximation (vdW) and we benchmark the results against existing predictions from Coupling Elec...
1812.07818v1
2019-10-01
In-situ detection of nucleation in high temperature solutions
The state of a sample during crystal growth from high temperature solutions is not accessible in conventional furnace systems. An optimization of the growth parameters often requires arduous trial and error procedures in particular in case of novel multicomponent systems with unknown phase diagrams. Here we present a m...
1910.00316v1
2019-10-04
Improvement of temperature uniformity of induction-heated T-shape susceptor for high-temperature MOVPE
The induction heating is a common method applied in metalorganic vapor phase epitaxy (MOVPE) especially for higher-temperature growth conditions. However, compared to the susceptor heated by the multiple-zone resistant heater, the inductive-heated susceptor could suffer from severe thermal non-uniformity issue. In this...
1910.02024v1
2019-10-21
Harnessing energy landscape exploration to control the buckling of cylindrical shells
The complexity and unpredictability of postbuckling responses in even simple thin shells have raised great challenges to emerging technologies exploiting buckling transitions. Here we comprehensively survey the buckling landscapes to show the full complexity of the stable buckling states and the transition mechanisms b...
1910.09210v1
2019-11-07
Long- to short-junction crossover and field-reentrant critical current in Al/Ag-nanowires/Al Josephson junctions
We have probed the superconducting proximity effect through long high-quality monocrystalline Ag nanowires, by realizing Josephson junctions of different lengths, with different superconducting materials. Thanks to the high number of junctions probed, both the contact resistance and electron diffusion constant could be...
1911.02962v1
2019-11-13
Giant enhancement of cryogenic thermopower by polar structural instability in the pressurized semimetal MoTe2
We found that a high mobility semimetal 1T'-MoTe2 shows a significant pressure-dependent change in the cryogenic thermopower in the vicinity of the critical pressure, where the polar structural transition disappears. With the application of a high pressure of 0.75 GPa, while the resistivity becomes as low as 10 {\mu}{\...
1911.05269v1
2019-11-26
One-directional thermal transport in densely aligned single-wall carbon nanotube films
Individual carbon nanotubes (CNTs) possess extremely high thermal conductivities. However, the thermal conductivities and their anisotropy of macroscopic assemblies of CNTs have so far remained small. Here, we report results of directional thermal transport measurements on a nearly-perfectly aligned CNT film fabricated...
1911.11340v1
2020-05-05
Nanofilm Materials for Devices of Magnetic Field Measurement in Radiation Environment
The prospects of using nanofilms of indium-containing III-V semiconductors, gold and single-layer graphene in magnetic field sensors, intended for application in radiation environment were evaluated on the results of testing in neutron fluxes. Semiconductor sensors are capable of withstanding radiation levels typical f...
2005.02075v1
2020-11-11
Synthesis of high-entropy-alloy-type superconductors (Fe,Co,Ni,Rh,Ir)Zr2 with tunable transition temperature
We report on the synthesis and superconductivity of high-entropy-alloy-type (HEA-type) compounds TrZr2 (Tr = Fe, Co, Ni, Rh, Ir), in which the Tr site satisfies the criterion of HEA. Polycrystalline samples of HEA-type TrZr2 with four different compositions at the Tr site were synthesized by arc melting method. The pha...
2011.05590v1