7,421 research outputs found
McKay correspondence for Landau-Ginzburg models
In this paper we prove an analogue of the McKay correspondence for Landau-Ginzburg models. Our proof is based on the ideas introduced by T. Bridgeland, A. King and M. Reid, which reformulate and generalize the McKay correspondence in the language of derived categories, along with the techniques introduced by J.-C. Chen
AuNx stabilization with interstitial nitrogen atoms: A Density Functional Theory Study
Researchers have been studying 4d and 5d Series Transition Metal Nitrides lately as a result of the experimental production of AuN, PtN, CuN. In this paper, we used the Density Functional Theory (DFT) implementing a pseudopotential plane-wave method to study the incorporation of nitrogen atoms in the face-centered cube (fcc) lattice of gold (Au). First, we took the fcc structure of gold, and gradually located the nitrogen atoms in tetrahedral (TH) and octahedral (OH) interstitial sites. AuN stabilized in: 2OH (30%), 4OH and 4TH (50%), 4OH - 2TH (close to the wurtzite structure) and 6TH (60%). This leads us to think that AuN behaves like a Transition Metal Nitride since the nitrogen atoms look for tetrahedral sites. © Published under licence by IOP Publishing Ltd
Dynamical quarks effects on the gluon propagation and chiral symmetry restoration
We exploit the recent lattice results for the infrared gluon propagator with
light dynamical quarks and solve the gap equation for the quark propagator.
Chiral symmetry breaking and confinement (intimately tied with the analytic
properties of QCD Schwinger functions) order parameters are then studied.Comment: Contribution to QCD-TNT-III: "From quarks and gluons to hadronic
matter: A bridge too far?
Differences between thin films deposition systems in the production transition metal nitride
The progress in vacuum technology have enabled the development of advanced coatings processes such as plasma assisted systems, which can produce thin films of different composition and optimum properties, that cannot be collected for the same material. The techniques of Pulsed Arc, Ionic Implantation and Sputtering have differences to produce coatings. Currently, AuN films have been grown by different techniques such as ion implantation, Reactive Ion Sputtering and Pulsed Arc, which have differences in the grown of the film. Siller 2002 reported a binding energy of 396.6 eV to N1s narrow spectrum as the first direct observation of a gold nitride. In this work, AuN thin films were grown in a system Plasma-Assisted Physical Vapor Deposition by pulsed arc technique. A N1s spectra was obtained with binding energies of 398.1, which by means of the differences between the techniques of ion implantation, sputtering and pulsed arc is concluded have been assigned to gold nitride species
Obtaining Au thin films in atmosphere of reactive nitrogen through magnetron sputtering
4d and 5d series of the transition metals are used to the obtaining nitrides metallic, due to the synthesis of PtN, AgN and AuN in the last years. Different nitrides are obtained in the Plasma Assisted Physics Vapour Deposition system, due to its ionization energy which is necessary for their formation. In this paper a Magnetron Sputtering system was used to obtain Au thin films on Si wafers in Nitrogen atmosphere. The substrate temperature was varied between 500 to 950°C. The samples obtained at high temperatures (>500°C) show Au, Si and N elements, as it is corroborated in the narrow spectrum obtained for X-Ray Photoelectron Spectroscopy; besides the competition of orientation crystallographic texture between (111) and (311) directions was present in the X-Ray Diffraction analysis to the sample heated at 950°C
A brief comment on the similarities of the IR solutions for the ghost propagator DSE in Landau and Coulomb gauges
This brief note is devoted to reconcile the conclusions from a recent
analysis of the IR solutions for the ghost propagator Dyson-Schwinger equations
in Coulomb gauge with previous studies in Landau gauge.Comment: 4 pages, 1 figur
Hydrostatic pressure to trigger and assist magnetic transitions: baromagnetic refrigeration
The possible application of the barocaloric effect to produce solid state
refrigerators is a topic of interest in the field of applied physics. In this
work, we present experimental data about the influence of external pressure on
the magnetic properties of a manganite with phase separation. Using the Jahn
Teller effect associated with the presence of the charge ordering we were able
to follow the transition to the ferromagnetic state induced by pressure. We
also demonstrated that external pressure can assist the ferromagnetic state,
decreasing the magnetic field necessary to generate the magnetic transition.Comment: Acepted to be published in Applied Physics Letter
Simultaneous electric and magnetic field induced nonvolatile memory
We investigate the electric field induced resistive switching effect and
magnetic field induced fraction enlargement on a polycrystalline sample of a
colossal magnetoresistive compound displaying intrinsic phase coexistence. Our
data show that the electric effect (presumably related to the presence of
inhomogeinities) is present in a broad temperature range(300 to 20 K), being
observable even in a mostly homogeneous ferromagnetic state. In the temperature
range in which low magnetic field determines the phase coexistence fraction,
both effects, though related to different mechanisms, are found to determine
multilevel nonvolatile memory capabilities simultaneously.Comment: Submited to AP
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