publicationDate stringlengths 10 10 | title stringlengths 17 233 | abstract stringlengths 20 3.22k | id stringlengths 9 12 |
|---|---|---|---|
2003-12-28 | Optical properties of pyrochlore oxide $Pb_{2}Ru_{2}O_{7-δ}$ | We present optical conductivity spectra for $Pb_{2}Ru_{2}O_{7-{\delta}}$
single crystal at different temperatures. Among reported pyrochlore ruthenates,
this compound exhibits metallic behavior in a wide temperature range and has
the least resistivity. At low frequencies, the optical spectra show typical
Drude response... | 0312662v1 |
2004-01-31 | Unprecedented Superconductivity in the beta-Pyrochlore Osmate KOs2O6 | Superconductivity in the potassium osmium oxide KOs2O6 crystallizing in the
beta-pyrochlore structure is studied by means of electrical resistivity,
magnetic susceptibility and specific heat. It is the second superconductor in
the family of pyrochlore oxides, following the alfa-type pyrochlore oxide
Cd2Re2O7 which is b... | 0402006v3 |
2004-03-31 | Spin-Transfer Effects in Nanoscale Magnetic Tunnel Junctions | We report measurements of magnetic switching and steady-state magnetic
precession driven by spin-polarized currents in nanoscale magnetic tunnel
junctions with low-resistance, < 5 Ohm-micron-squared, barriers. The current
densities required for magnetic switching are similar to values for
all-metallic spin-valve device... | 0404002v2 |
2004-08-16 | Structural, transport, magnetic properties and Raman spectroscopy of orthorhombic Y$1-x$CaxMnO3(0 <= x <= 0.5) | Orthorhombic Y$_{1-x}$Ca$_x$MnO$_3$ ($0 \leq x \leq 0.5$) was prepared under
high pressure and the variations with $x$ of its structural, magnetic,
electrical properties and the polarized Raman spectra were investigated. The
lattice parameters change systematically with $x$. Although there are strong
indications for in... | 0408360v1 |
2004-09-08 | Evidence for charge Kondo effect in superconducting Tl-doped PbTe | We report results of low-temperature thermodynamic and transport measurements
of Pb_{1-x}Tl_{x}Te single crystals for Tl concentrations up to the solubility
limit of approximately x = 1.5%. For all doped samples, we observe a
low-temperature resistivity upturn that scales in magnitude with the Tl
concentration. The tem... | 0409174v2 |
2004-09-08 | Tailoring of ferromagnetic Pr0.85Ca0.15MnO3/ferroelectric Ba0.6Sr0.4TiO3 superlattices for multiferroic properties | Superlattices composed of ferromagnetic Pr0.85Ca0.15MnO3 and ferroelectric
Ba0.6Sr0.4TiO3 layers were fabricated on (100) SrTiO3 substrates by a
pulsed-laser deposition method. The capacitance and resistive parts of the
samples were analyzed from the complex impedance measurements, performed on the
samples using a spec... | 0409182v1 |
2004-09-20 | Effect of Joule heating in current-driven domain wall motion | It was found that high current density needed for the current-driven domain
wall motion results in the Joule heating of the sample. The sample temperature,
when the current-driven domain wall motion occurred, was estimated by measuring
the sample resistance during the application of a pulsed-current. The sample
tempera... | 0409494v1 |
2004-11-12 | Observation of abrupt first-order metal-insulator transition in GaAs-based two-terminal device | An abrupt first-order metal-insulator transition (MIT) as a jump of the
density of states is observed for Be doped GaAs, which is known as a
semiconductor, by inducing very low holes of approximately n_p=5x10^{14}
cm^{-3} into the valence band by the electric field; this is anomalous. In a
higher hole doping concentrat... | 0411328v2 |
2004-11-13 | Large magnetoresistance anomalies in Dy7Rh3 | The compound Dy7Rh3 ordering antiferromagnetically below (TN=) 59 K has been
known to exhibit a temperature (T) dependent electrical resistivity (rho)
behavior in the paramagnetic state unusual for intermetallic compounds in the
sense that there is a broad peak in rho(T) in the paramagnetic state (around
130 K) as thou... | 0411360v1 |
2004-11-24 | Large magnetoresistance in the magnetically ordered state as well as in the paramagnetic state near 300 K in an intermetallic compound,Gd7Rh3 | We report the response of electrical resistivity $\rho$ to the application of
magnetic fields (H) up to 140 kOe in the temperature interval 1.8-300 K for the
compound, Gd7Rh3, ordering antiferromagnetically below 150 K. We find that
there is an unusually large decrease of $\rho$ for moderate values of H in the
close vi... | 0411608v1 |
2005-04-05 | Coherent transport in homojunction between excitonic insulator and semimetal | From the solution of a two-band model, we predict that the thermal and
electrical transport across the junction of a semimetal and an excitonic
insulator will exhibit high resistance behavior and low entropy production at
low temperatures, distinct from a junction of a semimetal and a normal
semiconductor. This phenome... | 0504121v1 |
2005-04-25 | Impurity scattering and quantum confinement in giant magnetoresistance systems | Ab initio calculations for the giant magnetoresistance (GMR) in Co/Cu, Fe/Cr,
and Fe/Au multilayers are presented. The electronic structure of the
multilayers and the scattering potentials of point defects therein are
calculated self-consistently. Residual resistivities are obtained by solving
the quasi-classical Boltz... | 0504634v1 |
2005-05-16 | Novel procedure to prepare cadmium stannate films using spray pyrolysis technique for solar cell applications | Thin films of cadmium stannate was prepared using low cost cadmium acetate
and tin (II) chloride precursors by spray pyrolysis technique at three
different substrate temperatures of 400, 450 and 5000 C. A novel procedure of
simultaneously forming additional layer, introduced for the first time in this
work, on the alre... | 0505383v1 |
2005-05-30 | Mechanisms limiting the coherence time of spontaneous magnetic oscillations driven by DC spin-polarized currents | The spin-transfer torque from a DC spin-polarized current can generate
highly-coherent magnetic precession in nanoscale magnetic-multilayer devices.
By measuring linewidths of spectra from the resulting resistance oscillations,
we argue that the coherence time can be limited at low temperature by thermal
deflections ab... | 0505733v2 |
2005-06-05 | On the unusual behavior of nitride compounds | This report presents consistent insight into the mechanism behind the unusual
behavior of nitride compounds from the perspective of tetrahedron bond
formation and its consequence on valence density of states. An extension of the
recent bond-band-barrier (BBB) correlation mechanism for oxidation [Sun CQ,
Prog Mater Sci ... | 0506109v1 |
2005-06-10 | Anisotropic Magnetoresistance and Magnetic Anisotropy in High-quality (Ga,Mn)As Films | We have performed a systematic investigation of magnetotransport of a series
of as-grown and annealed Ga1-xMnxAs samples with 0.011 <= x <= 0.09. We find
that the anisotropic magnetoresistance (AMR) generally decreases with
increasing magnetic anisotropy, with increasing Mn concentration and on low
temperature annealin... | 0506250v1 |
2005-06-14 | The O-M-O triatomic molecule: Basic unit of cuprates & manganates | The O(oxygen)-M(metal)-O(oxygen) molecule is a basic unit of high-temperature
superconducting cuprates and colossal magnetoresistance exhibiting manganates.
This molecule can be regarded either as an element of a linear chain or as an
ingredient of the corresponding cuprate or manganate lattice. The symmetry of
the uni... | 0506308v1 |
2005-09-27 | Critical currents and vortex dynamics in percolative superconductors containing fractal clusters of a normal phase | The effect of fractal clusters on magnetic and transport properties of
percolative superconductors is considered. The superconductor contains
percolative superconducting cluster, carrying a transport current, as well as
clusters of a normal phase, which act as pinning centers. A prototype of such a
structure is a high-... | 0509701v1 |
2005-10-18 | Surface Roughness and Hydrodynamic Boundary Conditions | We report results of investigations of a high-speed drainage of thin aqueous
films squeezed between randomly nanorough surfaces. A significant decrease in
hydrodynamic resistance force as compared with predicted by Taylor's equation
is observed. However, this reduction in force does not represents the slippage.
The mea... | 0510462v2 |
2005-10-20 | Current-driven magnetization switching in CoFeB/MgO/CoFeB magnetic tunnel junctions | Current-driven magnetization switching in low-resistance
Co40Fe40B20/MgO/Co40Fe40B20 magnetic tunnel junctions (MTJs) is reported. The
critical-current densities Jc required for current-driven switching in samples
annealed at 270C and 300C are found to be as low as 7.8 x 10^5 A/cm^2 and 8.8 x
10^5 A/cm^2 with accompany... | 0510538v1 |
2006-02-13 | Doping of Ce in T-La2CuO4: Rigorous test for electron-hole symmetry for high-Tc superconductivity | We report that Ce doping was achieved in La2CuO4 with the K2NiF4 (T)
structure for the first time by molecular beam epitaxy. A synthesis temperature
of as low as ~ 630C and an appropriate substrate choice, i.e., (001)LaSrGaO4 (a
\~ 3.843 A), enebled us to incorporate Ce into K2NiF4 lattice and to obtain
Ce-doped T-La2-... | 0602303v1 |
2006-03-02 | Coupled dynamics of electrons and phonons in metallic nanotubes: current saturation from hot phonons generation | We show that the self-consistent dynamics of both phonons and electrons is
the necessary ingredient for the reliable description of the hot phonons
generation during electron transport in metallic single-wall carbon nanotubes
(SWNTs). We solve the coupled Boltzmann transport equations to determine in a
consistent way t... | 0603046v1 |
2006-03-05 | Electro-Thermal Transport in Metallic Single-Wall Carbon Nanotubes for Interconnect Applications | This work represents the first electro-thermal study of metallic single-wall
carbon nanotubes (SWNTs) for interconnect applications. Experimental data and
careful modeling reveal that self-heating is of significance in short (1 < L <
10 um) nanotubes under high-bias. The low-bias resistance of micron scale SWNTs
is als... | 0603110v1 |
2006-03-24 | Single-crystalline nanopillars for spin-transfer measurements | We report on current-induced magnetization switching (CIMS) in single-
crystalline nanopillars. Fe(14 nm)/Cr(0.9 nm)/Fe(10 nm)/Ag(6 nm)/Fe(2 nm)
multilayers are deposited by molecular-beam epitaxy. The central Fe layer is
coupled to the thick one by interlayer exchange coupling over Cr. The topmost
Fe layer is decouple... | 0603662v1 |
2006-07-03 | Knight shift detection using gate-induced decoupling of the hyperfine interaction in quantum Hall edge channels | A method for the observation of the Knight shift in nanometer-scale region in
semiconductors is developed using resistively detected nuclear magnetic
resonance (RDNMR) technique in quantum Hall edge channels. Using a gate-induced
decoupling of the hyperfine interaction between electron and nuclear spins, we
obtain the ... | 0607028v1 |
2006-12-01 | New Type Phase Transition of Li2RuO3 with Honeycomb Structure | A new-type structural transition has been found in Li2RuO3 with honeycomb
lattice of edge-sharing RuO6-octahedra. With decreasing temperature T, the
electrical resistivity exhibits an anomalous increase at T=Tc~540 K, suggesting
the (metal to insulator)-like transition and the magnetic susceptibility also
shows a sharp... | 0612026v1 |
2006-12-26 | Transport properties of n-type ultrananocrystalline diamond films | We investigate transport properties of ultrananocrystalline diamond films for
a broad range of temperatures. Addition of nitrogen during plasma-assisted
growth increases the conductivity of ultrananocrystalline diamond films by
several orders of magnitude. We show that films produced at low concentration
of nitrogen in... | 0612633v1 |
2007-01-29 | Parameters of the Dzyaloshinsky-Moriya type weak ferromagnetism for some perovskite compounds | Compounds with distorted perovskite structure of the 4-f and 3-d transition
metals with the common formula LnTO3 (where Ln is rare-earth element, T is an
element from the Fe group) are the most multifold binary oxides of these two
groups elements. Wide range of stability for this structure allows the
realization of com... | 0701708v1 |
2007-02-20 | Organic small molecule field-effect transistors with Cytop(TM) gate dielectric: eliminating gate bias stress effects | We report on organic field-effect transistors with unprecedented resistance
against gate bias stress. The single crystal and thin-film transistors employ
the organic gate dielectric Cytop(TM). This fluoropolymer is highly water
repellent and shows a remarkable electrical breakdown strength. The single
crystal transisto... | 0702472v1 |
2007-02-25 | Broadband dielectric microwave microscopy on $μ$m length scales | We demonstrate that a near-field microwave microscope based on a transmission
line resonator allows imaging in a substantially wide range of frequencies, so
that the microscope properties approach those of a spatially-resolved impedance
analyzer. In the case of an electric probe, the broadband imaging can be used
in a ... | 0702573v1 |
2007-06-05 | Structure-Property Relationship in the Ordered-Perovskite- Related Oxide Sr3.12Er0.88Co4O10.5 | Synchrotron X-ray diffraction patterns were measured and analyzed for a
polycrystalline sample of the room-temperature ferromagnet Sr3.12Er0.88Co4O10.5
from 300 to 650 K, from which two structural phase transitions were found to
occur successively. The higher-temperature transition at 509 K is driven by
ordering of the... | 0706.0605v2 |
2007-08-14 | Origin of the Non-Linear Pressure Effects in Perovskite Manganites: Buckling of Mn-O-Mn Bonds and Jahn-Teller Distortion of the MnO6 Octahedra Induced by Pressure | High-pressure resistivity and x-ray diffraction have been measured on
La0.85MnO3-d. At low pressures the metal-insulator transition temperature (TMI)
increases linearly with pressure up to a critical pressure, P* ~ 3.4 GPa, which
is followed by reduction of TMI with increasing pressure. Analysis of the bond
distances a... | 0708.1963v2 |
2007-08-15 | Insulator to semiconductor transition and magnetic properties of the one-dimensional S = 1/2 system In_2VO_5 | We report structural, magnetization, electrical resistivity and nuclear- and
electron spin resonance data of the complex transition metal oxide In_2VO_5 in
which structurally well-defined V-O chains are realized. An itinerant character
of the vanadium d-electrons and ferromagnetic correlations, revealed at high
tempera... | 0708.2088v1 |
2007-11-15 | Recrystallization of glass: homogeneous vs. heterogeneous nucleation in La(0.5)Ca(0.5)MnO3 | We probe through magnetization and resistivity measurements a kinetically
arrested glass-like but long-range ordered magnetic state. The transformation
kinetics of the magnetic field-temperature induced broad first-order transition
from ferromagnetic-metallic (FMM) to antiferromagnetic-insulating (AFI) state
gets hinde... | 0711.2347v1 |
2007-11-28 | Radiation Damage in Polarized Ammonia Solids | Solid NH3 and ND3 provide a highly polarizable, radiation resistant source of
polarized protons and deuterons and have been used extensively in high
luminosity experiments investigating the spin structure of the nucleon. Over
the past twenty years, the UVA polarized target group has been instrumental in
producing and p... | 0711.4413v1 |
2008-03-06 | Field emission from single multi-wall carbon nanotubes | Electron field emission characteristics of individual multiwalled carbon
nanotubes have been investigated by a piezoelectric nanomanipulation system
operating inside a scanning electron microscopy chamber. The experimental setup
ensures a high control capability on the geometric parameters of the field
emission system ... | 0803.0810v1 |
2008-04-10 | Electronic properties and phase transitions in low-dimensional semiconductors | We present the first review of the current state of the literature on
electronic properties and phase transitions in TlX and TlMX2 (M = Ga, In; X =
Se, S, Te) compounds. These chalcogenides belong to a family of the
low-dimensional semiconductors possessing chain or layered structure. They are
of significant interest b... | 0804.1639v2 |
2008-04-23 | Superconductivity at 53.5 K in GdFeAsO1-delta | Here we report the fabrication and superconductivity of the iron-based
arsenic-oxide GdFeAsO1-delta compound with oxygen-deficiency, which has an
onset resistivity transition temperature at 53.5 K. This material has a same
crystal structure as the newly discovered high-Tc ReFeAsO1-delta family (Re =
rare earth metal) a... | 0804.3727v3 |
2008-05-28 | Effect of pressure on the superconducting critical temperature of La[O_{0.89}F_{0.11}]FeAs and Ce[O_{0.88}F_{0.12}]FeAs | We have performed several high-pressure resistivity experiments on the
recently discovered superconductors La[O_{0.89}F_{0.11}]FeAs and
Ce[O_{0.88}F_{0.12}]FeAs. At ambient pressure, these materials have
superconducting onset temperatures T_c of 28 K and 44 K, respectively. While
the T_c of La[O_{0.89}F_{0.11}]FeAs goe... | 0805.4372v3 |
2008-06-18 | UV-photon and electrically driven resistance switching in ZnO nanotube arrays | Vertically aligned ZnO nanotube arrays fabricated on an ITO substrate are
found to exhibit strong persistent photoconductivity (PPC) effect and
electrically driven conductance switching behavior, though the latter shows a
gradual decay from high conductance state to a low conductance state. Unlike
the electrical switch... | 0806.2907v2 |
2008-06-20 | Ferromagnetic spin fluctuation in LaFeAsO1-xFx | The F doped LaFeAsO, a recently discovered superconductor with the high Tc of
26 K, has been studied by the resistivity, magnetic susceptibility, and heat
capacity measurements in the F doping range from 0 to 0.14 (x in LaFeAsO1-xFx).
In the low temperature region, a T3lnT term in the heat capacity and a T2 term
in the... | 0806.3304v1 |
2008-06-27 | Magnetoresistance oscillations and relaxation effects at the SrTiO3-LaAlO3 interface | We present low-temperature and high-field magnetotransport data on
SrTiO3-LaAlO3 interfaces. The resistance shows hysteresis in magnetic field and
a logarithmic relaxation as a function of time. Oscillations in the
magnetoresistance are observed, showing a square root periodicity in the
applied magnetic field, both in ... | 0806.4450v1 |
2008-07-24 | Fishtail effect and the vortex phase diagram of single crystal Ba0.6K0.4Fe2As2 | By measuring the magnetization hysteresis loops of superconducting
Ba0.6K0.4Fe2As2 single crystals, we obtained the high upper critical field and
large current carrying ability, which point to optimistic applications. The
fishtail (or second peak) effect is also found in the material, and the
position of the vortex pin... | 0807.3786v3 |
2008-07-25 | Adaptation of the Bridgman anvil cell to liquid pressure mediums | The advantage of Bridgman anvil pressure cells is their wide pressure range
and the large number of wires which can be introduced into the pressure
chamber. In these pressure cells soft solid pressure mediums like steatite are
used. We have succeeded in adapting the Bridgman cell to liquid pressure
mediums. With this b... | 0807.4137v1 |
2008-08-15 | Localization and the Anomalous Hall Effect in a "Dirty" Metallic Ferromagnet | We report magnetoresistance measurements over an extensive temperature range
(0.1 K $\leq T \leq$ 100 K) in a disordered ferromagnetic semiconductor (\gma).
The study focuses on a series of metallic \gma~ epilayers that lie in the
vicinity of the metal-insulator transition ($k_F l_e\sim 1$). At low
temperatures ($T < 4... | 0808.2079v2 |
2008-08-22 | Phase Coherence Effects in the Vortex Transport Entropy | Nernst and electrical resistivity measurements in superconducting YBCO and
BSCCO with and without columnar defects show a distinctive thermodynamics of
the respective liquid vortex matter. At a field dependent high temperature
region in the phase diagram the Nernst signal is independent of structural
defects in both ma... | 0808.3015v1 |
2009-02-05 | Itinerant antiferromagnetism in BaCr$_2$As$_2$ | We report single crystal synthesis, specific heat and resistivity
measurements and electronic structure calculations for BaCr$_2$As$_2$. This
material is a metal with itinerant antiferromagnetism, similar to the parent
phases of Fe-based high temperature superconductors, but differs in magnetic
order. Comparison of bar... | 0902.0945v2 |
2009-04-05 | Superconductivity in Ir-doped LaFe1-xIrxAsO | We report the realization of superconductivity by 5d element Ir doping in
LaFeAsO, a prototype parent compound of high-temperature iron based
superconductors. X-ray diffraction patterns indicate that the material has
formed the ZrCuSiAs-type structure with a space group P4/nmm. The systematic
evolution of the lattice c... | 0904.0772v4 |
2009-04-06 | Gap opening in the zeroth Landau level of graphene | We have measured a strong increase of the low-temperature resistivity
$\rho_{xx}$ and a zero-value plateau in the Hall conductivity $\sigma_{xy}$ at
the charge neutrality point in graphene subjected to high magnetic fields up to
30 T. We explain our results by a simple model involving a field dependent
splitting of the... | 0904.0948v1 |
2009-07-09 | Agglomeration and filtration of colloidal suspensions with DVLO interactions in simulation and experiment | Cake filtration is a widely used solid-liquid separation process. However,
the high flow resistance of the nanoporous filter cake lowers the efficiency of
the process significantly. The structure and thus the permeability of the
filter cakes depend on the compressive load acting on the particles, the
particles size, an... | 0907.1551v2 |
2009-07-12 | Vortex-like state observed in ferromagnetic contacts | Point-contacts (PC) offer a simple way to create high current densities, 10^9
A/cm^2 and beyond, without substantial Joule heating. We have shown recently
(Nano Letters, 7 (2007) 927) that conductivity of nanosized PCs between a
normal and ferromagnetic metals exhibits bi-stable hysteretic states versus
both bias curre... | 0907.2027v2 |
2009-07-16 | Dynamical correlations in electronic transport through a system of coupled quantum dots | Current auto- and cross-correlations are studied in a system of two
capacitively coupled quantum dots. We are interested in a role of Coulomb
interaction in dynamical correlations, which occur outside the Coulomb blockade
region (for high bias). After decomposition of the current correlation
functions into contribution... | 0907.2879v1 |
2009-07-30 | Solvothermal Reduction of Chemically Exfoliated Graphene Sheets | Graphene has attracted much attention due to its interesting properties and
potential applications. Chemical exfoliation methods have been developed to
make graphene recently, aimed at large-scale assembly and applications such as
composites and Li ion batteries. Although efficient, the chemical exfoliation
methods inv... | 0907.5417v1 |
2009-09-23 | Intermediate-valence behavior of the transition-metal oxide CaCu$_3$Ru$_4$O$_{12}$ | The transition--metal oxide CaCu$_3$Ru$_4$O$_{12}$ with perovskite--type
structure shows characteristic properties of an intermediate--valence system.
The temperature--dependent susceptibility exhibits a broad maximum around $150
- 160$ K. At this temperature, neutron powder diffraction reveals a small but
significant ... | 0909.4208v1 |
2009-10-09 | Observation of a d-wave nodal liquid in highly underdoped Bi_2Sr_2CaCu_2O_{8+δ} | We use angle resolved photoemission spectroscopy to probe the electronic
excitations of the non-superconducting state that exists between the
antiferromagnetic Mott insulator at zero doping and the superconducting state
at larger dopings in Bi_2Sr_2CaCu_2O_{8+\delta}. We find that this state is a
nodal liquid whose exc... | 0910.1648v1 |
2009-10-26 | Wafer-scale synthesis and transfer of graphene films | We developed means to produce wafer scale, high-quality graphene films as
large as 3 inch wafer size on Ni and Cu films under ambient-pressure and
transfer them onto arbitrary substrates through instantaneous etching of metal
layers. We also demonstrated the applications of the large-area graphene films
for the batch f... | 0910.4783v1 |
2009-11-25 | RETGEM with polyvinylchloride (PVC) electrodes | This paper presents a new design of the RETGEM (Resistive Electrode Thick
GEM) based on electrodes made of a polyvinylchloride material (PVC). Our device
can operate with gains of 10E5 as a conventional TGEM at low counting rates and
as RPC in the case of high counting rates without of the transit to the violent
sparks... | 0911.4807v1 |
2009-12-03 | Atomic-scale patterning of hydrogen terminated Ge(001) by scanning tunneling microscopy | In this paper we demonstrate atomic-scale lithography on hydrogen terminated
Ge(001. The lithographic patterns were obtained by selectively desorbing
hydrogen atoms from a H resist layer adsorbed on a clean, atomically flat
Ge(001) surface with a scanning tunneling microscope tip operating in
ultra-high vacuum. The inf... | 0912.0754v1 |
2009-12-10 | Highly Uniform 300 mm Wafer-Scale Deposition of Single and Multilayered Chemically Derived Graphene Thin Films | The deposition of atomically thin highly uniform chemically derived graphene
(CDG) films on 300 mm SiO2/Si wafers is reported. We demonstrate that the very
thin films can be lifted off to form uniform membranes than can be
free-standing or transferred onto any substrate. Detailed maps of thickness
using Raman spectrosc... | 0912.2087v1 |
2009-12-21 | Microstructure and superconductivity of Ir-doped BaFe2As2 superconductor | Polycrystalline samples with nominal composition of Ba(Fe1-xIrx)2As2 (x=0.10,
0.15, and 0.20) were investigated by means of X-ray diffraction (XRD), scanning
electron microscopy (SEM), electrical resistivity, and magnetization
measurements. XRD and SEM results showed that almost single phase samples were
obtained. Bulk... | 0912.4113v1 |
2010-01-21 | Photon assisted tunneling as an origin of the Dynes density of states | We show that the effect of a high-temperature environment in current
transport through a normal metal-insulator-superconductor tunnel junction can
be described by an effective density of states (DOS) in the superconductor. In
the limit of a resistive low-ohmic environment, this DOS reduces into the
well-known Dynes for... | 1001.3853v3 |
2010-02-07 | Time-Dependent Transport Through Molecular Junctions | We investigate transport properties of molecular junctions under two types of
bias--a short time pulse or an AC bias--by combining a solution for the Green
functions in the time domain with electronic structure information coming from
ab initio density functional calculations. We find that the short time response
depen... | 1002.1441v1 |
2010-03-16 | All Magnesium diboride Josephson Junctions with MgO and native oxide barriers | We present results on all-MgB2 tunnel junctions, where the tunnel barrier is
deposited MgO or native-oxide of base electrode. For the junctions with MgO,
the hysteretic I-V curve resembles a conventional underdamped Josephson
junction characteristic with critical current-resistance product nearly
independent of the jun... | 1003.3158v1 |
2010-03-31 | Magneto-transport Effects in Topological Insulator Bi$_2$Se$_3$ Nanoribbons | Magneto-resistance (MR) of Bi$_2$Se$_3$ nanoribbons is studied over a broad
range of temperature ($T$=300K-2K) and under various magnetic field ($B$)
orientations. The MR is strongly anisotropic with the perpendicular MR much
larger than the longitudinal and transverse MRs. The perpendicular MR exhibits
quadratic $B$-d... | 1003.6099v4 |
2010-04-05 | Hysteresis in the magneto-transport of Manganese-doped Germanium: evidence for carrier-mediated ferromagnetism | We report the fabrication of Ge:Mn ferromagnetic semiconductors by Mn-ion
implantation into Ge followed by pulsed laser annealing. Benefiting from the
short time annealing, the hole concentration in Mn-implanted Ge has been
increased by two orders of magnitude from 10$^{18}$ to over 10$^{20}$
cm$^{-3}$. Likely due to t... | 1004.0568v1 |
2010-04-21 | Effect of pressure on the magnetic, transport, and thermal-transport properties of the electron-doped manganite CaMn$_{1-x}$Sb$_{x}$O$_{3}$ | We have demonstrated the effect of hydrostatic pressure on magnetic and
transport properties, and thermal transport properties in electron-doped
manganites CaMn$_{1-x}$Sb$_{x}$O$_{3}$. The substitution of Sb$^{5+}$ ion for
Mn $^{4+}$site of the parent matrix causes one-electron doping with the
chemical formula CaMn$^{4... | 1004.3669v3 |
2010-05-06 | Theoretical and Experimental Studies of Schottky Diodes That Use Aligned Arrays of Single Walled Carbon Nanotubes | We present theoretical and experimental studies of Schottky diodes that use
aligned arrays of single walled carbon nanotubes. A simple physical model,
taking into account the basic physics of current rectification, can adequately
describe the single-tube and array devices. We show that for as grown array
diodes, the re... | 1005.0870v1 |
2010-06-16 | Perfect Domain-Lattice Matching Between MgB2 and Al2O3: Single-Crystal MgB2 Thin Films Grown on Sapphire | We have found that single-crystal films can be grown on (0001) Al2O3
substrates through the golden relation of a perfect lattice-matching ratio
between the a-axis lattice constants of MgB2 and Al2O3. Selected area electron
diffraction patterns evidently indicate hexagonal MgB2 film with a 30 degrees
in-plane rotation w... | 1006.3169v1 |
2010-07-01 | Chip-scale nanofabrication of single spins and spin arrays in diamond | We demonstrate a technique to nanofabricate nitrogen vacancy (NV) centers in
diamond based on broad-beam nitrogen implantation through apertures in electron
beam lithography resist. This method enables high-throughput nanofabrication of
single NV centers on sub-100 nm length scales. Secondary ion mass spectroscopy
(SIM... | 1007.0240v2 |
2010-08-04 | Transport in gapped bilayer graphene: the role of potential fluctuations | We employ a dual-gated geometry to control the band gap \Delta in bilayer
graphene and study the temperature dependence of the resistance at the charge
neutrality point, RNP(T), from 220 to 1.5 K. Above 5 K, RNP(T) is dominated by
two thermally activated processes in different temperature regimes and exhibits
exp(T3/T)... | 1008.0783v1 |
2010-09-13 | Cooper Pair Writing at the LaAlO3/SrTiO3 Interface | The LaAlO3/SrTiO3 interface provides a unique platform for controlling the
electronic properties of the superconducting semiconductor SrTiO3. Prior
investigations have shown that two-dimensional superconductivity can be
produced at the LaAlO3/SrTiO3 interface and tuned electrostatically. The
recently demonstrated rever... | 1009.2424v2 |
2010-09-16 | Overlapping-gate architecture for silicon Hall bar MOSFET devices in the low electron density regime | We report the fabrication and study of Hall bar MOSFET devices in which an
overlapping-gate architecture allows four-terminal measurements of low-density
2D electron systems, while maintaining a high density at the ohmic contacts.
Comparison with devices made using a standard single gate show that
measurements can be p... | 1009.3109v1 |
2010-10-01 | Contactless measurement of electrical conductance of a thin film of amorphous germanium | We present a contactless method for measuring charge in a thin film of
amorphous germanium (a-Ge) with a nanoscale silicon MOSFET charge sensor. This
method enables the measurement of conductance of the a-Ge film even in the
presence of blocking contacts. At high bias voltage, the resistance of the
contacts becomes neg... | 1010.0045v1 |
2010-10-05 | Optical property modification of ZnO: Effect of 1.2 MeV Ar irradiation | We report a systematic study on 1.2 MeV Ar^8+ irradiated ZnO by x-ray
diffraction (XRD), room temperature photoluminescence (PL) and
ultraviolet-visible (UV-Vis) absorption measurements. ZnO retains its wurtzite
crystal structure up to maximum fluence of 5 x 10^16 ions/cm^2. Even, the width
of the XRD peaks changes lit... | 1010.0753v1 |
2010-11-23 | Transport in Graphene Tunnel Junctions | We present a technique to fabricate tunnel junctions between graphene and Al
and Cu, with a Si back gate, as well as a simple theory of tunneling between a
metal and graphene. We map the differential conductance of our junctions versus
probe and back gate voltage, and observe fluctuations in the conductance that
are di... | 1011.5067v1 |
2010-12-14 | Reentrant spin-glass behavior in $TlFe_{2-x}Se_2$ with the $ThCr_2Si_2$-type structure | We investigated the physical properties of $TlFe_{2-x}Se_2$ single crystals.
The resistivity of $TlFe_{2-x}Se_2$ shows typical semiconductor behavior with
an activation energy of 25 meV. DC susceptibility indicates an
antiferromagnetic transition at about 450 K. Reentrant spin-glass (RSG)
behavior was found at about 13... | 1012.2929v1 |
2010-12-23 | Effect of chromium disorder on the thermoelectric properties of Layered-antiferromagnet CuCrS2 | Layered-antiferromagnetic compound CuCrS2 has been prepared by different
methods. The analysis of X-ray diffraction patterns of different samples gave
significant amount of vacancy-disorder of Cr-atoms within the layers. Extended
period of sintering above 9000C increases the transfer of Cr-atoms to the
interstitial sit... | 1012.5147v1 |
2011-03-04 | Giant enhancement of spin accumulation and long-distance spin precession in metallic lateral spin valves | The nonlocal spin injection in lateral spin valves is highly expected to be
an effective method to generate a pure spin current for potential spintronic
application. However, the spin valve voltage, which decides the magnitude of
the spin current flowing into an additional ferromagnetic wire, is typically of
the order ... | 1103.0852v2 |
2011-03-23 | Local Electrical Stress-Induced Doping and Formation of 2D Monolayer Graphene P-N Junction | We demonstrated doping in 2D monolayer graphene via local electrical
stressing. The doping, confirmed by the resistance-voltage transfer
characteristics of the graphene system, is observed to continuously tunable
from N-type to P-type as the electrical stressing level (voltage) increases.
Two major physical mechanisms ... | 1103.4568v3 |
2011-03-25 | Giant Positive Magnetoresistance in Co@CoO Nanoparticle Arrays | We report the magnetotransport properties of self-assembled Co@CoO
nanoparticle arrays at temperatures below 100 K. Resistance shows thermally
activated behavior that can be fitted by the general expression of R
exp{(T/T0)^v}. Efros-Shklovskii variable range hopping (v=1/2) and simple
activation (hard gap, v=1) dominat... | 1103.5029v1 |
2011-05-06 | Optical excitation of Electron-Glasses | Electron-glasses can be readily driven far from equilibrium by a variety of
means. Several mechanisms to excite the system and their relative merits are
reviewed. In this study we focus on the process of exciting electron-glasses by
interaction with near infrared radiation. The efficiency of this protocol
varies consid... | 1105.1350v1 |
2011-05-22 | Evidence for a capacitor network near the metal insulator transition in VO2 thin films probed by in-plane impedance spectroscopy | Impedance spectroscopy measurements were performed in high quality Vanadium
dioxide (VO2) thin films. This technique allows us investigate the resistive
and capacitive contribution to the dielectric response near the metal-insulator
transition (MIT). A non ideal RC behavior was found in our films from room
temperature ... | 1105.4308v1 |
2011-05-24 | Rectification at Graphene-Semiconductor Interfaces: Zero-Gap Semiconductor Based Diodes | Using current-voltage (I-V) and capacitance-voltage (C-V) measurements, we
report on the unusual physics and promising technical applications associated
with the formation of Schottky barriers at the interface of a one-atom-thick
zero-gap semiconductor (graphene) and conventional semiconductors. When
chemical vapor dep... | 1105.4811v2 |
2011-05-27 | Magnonic spin-transfer torque MRAM with low power, high speed, and error-free switching | A new class of spin-transfer torque magnetic random access memory (STT-MRAM)
is discussed, in which writing is achieved using thermally initiated magnonic
current pulses as an alternative to conventional electric current pulses. The
magnonic pulses are used to destabilize the magnetic free layer from its
initial direct... | 1105.5473v1 |
2011-05-27 | Temperature Dependence of the Intrinsic Anomalous Hall Effect in Nickel | We investigate the unusual temperature dependence of the anomalous Hall
effect in Ni. By varying the thickness of the MBE-grown Ni films, the
longitudinal resistivity is uniquely tuned without resorting to doping
impurities; consequently, the intrinsic and extrinsic contributions are cleanly
separated out. In stark con... | 1105.5664v1 |
2011-05-31 | Interplay between topological insulators and superconductors | Topological insulators are insulating in the bulk but possess metallic
surface states protected by time-reversal symmetry. Here, we report a detailed
electronic transport study in high quality Bi2Se3 topological insulator thin
films contacted by superconducting (In, Al and W) electrodes. The resistance of
the film show... | 1105.6174v3 |
2011-06-04 | Facile fabrication of lateral nanowire wrap-gate devices with improved performance | We present a simple fabrication technique for lateral nanowire wrap-gate
devices with high capacitive coupling and field-effect mobility. Our process
uses e-beam lithography with a single resist-spinning step, and does not
require chemical etching. We measure, in the temperature range 1.5-250 K, a
subthreshold slope of... | 1106.0796v1 |
2011-06-04 | Mechanochemical reaction in graphane under uniaxial tension | The quantum-mechanochemical-reaction-coordinate simulations have been
performed to investigate the mechanical properties of hydrogen functionalized
graphene. The simulations disclosed atomically matched peculiarities that
accompany the deformation-failure-rupture process occurred in the body. A
comparative study of the... | 1106.0837v2 |
2011-07-09 | Huge Volume Expansion and Structural Transformation of Carbon Nanotube Aligned Arrays during Electrical Breakdown in Vacuum | We observed a huge volume expansion of aligned single walled carbon nanotube
(SWNT) arrays accompanied by structural transformation during electrical
breakdown in vacuum. The SWNT arrays were assembled between prefabricated Pd
source and drain electrodes of 2 \mu m separation on Si/SiO_2 substrate via
dielectrophoresis... | 1107.1758v1 |
2011-07-20 | Macroscopic Superconducting Current through a Silicon Surface Reconstruction with Indium Adatoms: Si(111)-(R7$\times$R3)-In | Macroscopic and robust supercurrents are observed by direct electron
transport measurements on a silicon surface reconstruction with In adatoms
(Si(111)-(R7xR3)-In). The superconducting transition manifests itself as an
emergence of the zero resistance state below 2.8 K. $I-V$ characteristics
exhibit sharp and hysteret... | 1107.3902v2 |
2011-07-30 | Indications of an Electronic Phase Transition in 2D YBa2Cu3O7-x Induced by Electrostatic Doping | We successfully tuned an underdoped ultrathin YBa2Cu3O7-x film into the
overdoped regime by means of electrostatic doping using an ionic liquid as a
dielectric material. This process proved to be reversible. Transport
measurements showed a series of anomalous features compared to chemically doped
bulk samples and a dif... | 1108.0083v1 |
2011-08-01 | Evolution of Structural and Physical Properties of Sr3(Ru1-xMnx)2O7 with Mn Concentration | Layered ruthenates are prototype materials with strong structure-property
correlations. We report the structural and physical properties of
double-layered perovskite Sr3(Ru1-xMnx)2O7 single crystals with 0<=x<=0.7.
Single crystal x-ray diffraction refinements reveal that Mn doping on the Ru
site leads to the shrinkage ... | 1108.0392v1 |
2011-08-15 | Large conductance modulation of gold thin films by huge charge injection via electrochemical gating | By using an electrochemical gating technique with a new combination of
polymer and electrolyte, we were able to inject surface charge densities n_2D
as high as 3.5 \times 10^15 e/cm^2 in gold films and to observe large relative
variations in the film resistance, DeltaR/R', up to 10% at low temperature.
DeltaR/R' is a l... | 1108.3099v1 |
2011-09-19 | Fe-doping induced superconductivity in charge-density-wave system 1T-TaS2 | We report the interplay between charge-density-wave (CDW) and
superconductivity of 1$T$-Fe$_{x}$Ta$_{1-x}$S$_{2}$ ($0\leq x \leq 0.05$)
single crystals. The CDW order is gradually suppressed by Fe-doping,
accompanied by the disappearance of pseudogap/Mott-gap as shown by the density
functional theory (DFT) calculations... | 1109.3962v3 |
2011-09-28 | A combination of capillary assembly and dielectrophoresis for wafer scale integration of carbon nanotubes-based electrical and mechanical devices | The wafer scale integration of carbon nanotubes (CNT) remains a challenge for
electronic and electromechanical applications. We propose a novel CNT
integration process relying on the combination of controlled capillary assembly
and buried electrode dielectrophoresis (DEP). This process enables to monitor
the precise sp... | 1109.6268v1 |
2011-11-14 | Thermoelectric properties of Ba-Cu-Si clathrates | Thermoelectric properties of the type-I clathrates Ba$_8$Cu$_x$Si$_{46-x}$
($3.6 \leq x \leq 7$, $x$ = nominal Cu content) are investigated both
experimentally and theoretically. The polycrystalline samples are prepared
either by melting, ball milling and hot pressing or by melt spinning, hand
milling and hot pressing ... | 1111.3278v1 |
2011-12-13 | The Disordered Induced Interaction and the Phase Diagram of Cuprates | There are processes in nature that resemble a true force but arise due to the
minimization of the local energy. The most well-known case is the exchange
interaction that leads to magnetic order in some materials. We discovered a new
similar process occurring in connection with an electronic phase separation
transition ... | 1112.2880v1 |
2012-05-08 | Normal and intrinsic anomalous Hall effect in Nb1-yFe2+y | The Hall effect on selected samples of the dilution series Nb1-yFe2+y is
studied. Normal and anomalous contributions are observed, with positive normal
Hall effect dominating at high temperatures. Consistent analysis of the
anomalous contribution is only possible for Fe-rich Nb0.985Fe2.015 featuring a
ferromagnetic gro... | 1205.1651v1 |
2012-05-10 | Physical properties and crystal chemistry of Ce2Ga12Pt | Single crystals of the new ternary compound Ce2Ga12Pt were prepared by the
self-flux technique. The crystal structure with the space group P4/nbm was
established from single-crystal X-ray diffraction data and presents a
derivative of the LaGa6Ni0.6 prototype. Magnetic susceptibility measurements
show Curie-Weiss behavi... | 1205.2301v1 |
2012-05-13 | Voltage-Induced Ferromagnetic Resonance in Magnetic Tunnel Junctions | We demonstrate excitation of ferromagnetic resonance in CoFeB/MgO/CoFeB
magnetic tunnel junctions (MTJs) by the combined action of voltage-controlled
magnetic anisotropy (VCMA) and spin transfer torque (ST). Our measurements
reveal that GHz-frequency VCMA torque and ST in low-resistance MTJs have
similar magnitudes, an... | 1205.2835v2 |
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