Surface and Grain Boundary Analysis of High Temperature Superconductors

The purpose of this paper is to survey the methods that are available for probing surfaces and grain boundaries of high temperature superconductors. Various surface-sensitive spectroscopies are applied to the analysis of YBa2Cu3O7-x and Bi2Sr2CaCu2O8+x including photoelectron spectroscopy, spatially-resolved electron energy loss spectroscopy, and scanning electron microscopy (SEM). One of the major sources of contamination at surfaces and grain boundaries is found to be BaCO3. The cleavage surface of single crystal Bi2Sr2CaCu2O8+x is inert and can be used to probe bulk properties of superconductors, even with surface-sensitive techniques. The orbital character of the superconducting oxygen 2p holes is found to be Px,y, with x,y in the a,b plane. Photoemission at the Fermi level indicates a Fermi liquid nature of these states

Behavior of Cu(P) and Oxygen Free High Conductivity Cu Anodes under Electrodeposition Conditions

Films formed on Cu(P) (with 0.1 atom percent P) and oxygen free high conductivity Cu anodes in electroplating solutions were studied by a newly developed gravimetric technique, electrochemical methods, x-ray photoelectron spectroscopy, and x-ray absorption spectroscopy. The black film formed on Cu(P) in Cl^− -containing solutions was found to resemble a porous sponge composed of CuCl but laden with concentrated CuSO_4 solution. The gravimetric experiments show that the difference between the buoyancy-corrected measured mass change and the charge-equivalent mass change has two components: a reversible part that comes and goes as the current is turned on and off, and an irreversible part that remains on the surface and increases in mass with time as dissolution proceeds. The reversible part of the mass change arises from the weight of the diffusion layer. The irreversible part results from the anodic film, which increases linearly in mass with charge density but at a rate that is independent of current density. P inhibits the disproportionation of Cu^+1 that results in the poorly adherent anodic film that forms on OFHC Cu anodes.Research was carried out in part at beamline X23A2 at the National Synchrotron Light Source, Brookhaven National Laboratory, which is supported by the U.S. Department of Energy, Division of Materials Sciences and Division of Chemical Sciences. H.S.I. was supported by the U.S. Department of Energy, Division of Materials Sciences, Office of Basic Energy Science under Contract No. DE-AC02-76CH00016

Corrosion and Passivation of Fe and FeN Films

The role of nitrogen in corrosion and passivation of thin Fe-N films was studied. Sputtered films with different levels of nitrogen were characterized for composition, conductivity, stress, and crystallinity. Corrosion and passivation of the films were evaluated by electrochemical measurements combined with in situ ellipsometry and ex situ x-ray photoelectron spectroscopy. The results indicate that in deaerated solutions the primary action of N is to reduce the catalytic activity of the surface for the hydrogen reaction and thereby reduce corrosion. In aerated solutions the corrosion rate increases with N content. Kinetics of the protective oxide formation as a function of potential, percent N, and the presence of borate buffer are discussed in detail. The work is relevant to the behavior of oxide-free Fe-N surfaces in contact with mild, nearly neutral electrolytes, such as could be used in fabrication of magnetic recording heads

X-Ray Absorption Study of Electrochemically Grown Oxide Films on Al-Cr Sputtered Alloys I. Ex situ Studies

Oxides grown electrochemically in a borate buffer solution on the surface of sputter-deposited AlCr alloy films were studied by x-ray absorption near edge structure (XANES). The measurements were made in air immediately following polarization in solution. The oxides were also examined with x-ray photoelectron spectroscopy (XPS). The effects of alloy composition and thickness as well as applied potential were studied. Cr( VI) was found in the oxides if the applied potential was sufficiently high. The Cr(VI) was enriched at the interface with the electrolyte and the proportion of Cr(VI) in the oxide was higher for alloy films containing more Cr. The Cr(VI) in the oxides could be reversibly reduced to Cr(III) and reoxidized to Cr(VI) by subsequent potentiostatic treatments in solution.Research was carried out in part at the National Synchroton Light Source, Brookhaven National Laboratory, which is supported by the U.S. Department of Energy, Division of Materials Sciences and Division of Chemical Sciences. A. J. D. and H. S. I. were supported by the U.S. Department of Energy, Division of Materials Sciences, Office of Basic Energy Science under Contract No. DE-AC02-76CH00016

Affective iconic words benefit from additional sound–meaning integration in the left amygdala

Recent studies have shown that a similarity between sound and meaning of a word (i.e., iconicity) can help more readily access the meaning of that word, but the neural mechanisms underlying this beneficial role of iconicity in semantic processing remain largely unknown. In an fMRI study, we focused on the affective domain and examined whether affective iconic words (e.g., high arousal in both sound and meaning) activate additional brain regions that integrate emotional information from different domains (i.e., sound and meaning). In line with our hypothesis, affective iconic words, compared to their non‐iconic counterparts, elicited additional BOLD responses in the left amygdala known for its role in multimodal representation of emotions. Functional connectivity analyses revealed that the observed amygdalar activity was modulated by an interaction of iconic condition and activations in two hubs representative for processing sound (left superior temporal gyrus) and meaning (left inferior frontal gyrus) of words. These results provide a neural explanation for the facilitative role of iconicity in language processing and indicate that language users are sensitive to the interaction between sound and meaning aspect of words, suggesting the existence of iconicity as a general property of human language

Pathway to the PiezoElectronic Transduction Logic Device

The information age challenges computer technology to process an exponentially increasing computational load on a limited energy budget - a requirement that demands an exponential reduction in energy per operation. In digital logic circuits, the switching energy of present FET devices is intimately connected with the switching voltage, and can no longer be lowered sufficiently, limiting the ability of current technology to address the challenge. Quantum computing offers a leap forward in capability, but a clear advantage requires algorithms presently developed for only a small set of applications. Therefore, a new, general purpose, classical technology based on a different paradigm is needed to meet the ever increasing demand for data processing.Comment: in Nano Letters (2015

Система управления повышением квалификации управленческого персонала организации

Выпускная квалификационная работа посвящена анализу путей повышения эффективности использования человеческих ресурсов. В ходе работы был произведен обзор теоретического материала по управлению человеческими ресурсами; проанализированы размер и структура организации; изучены методы мотивации рассматриваемой организации; проведена оценка удовлетворенности персонала; проанализированы методы, влияющие на эффективность работы персонала; предложены рекомендации по повышению эффективности использования людских ресурсов.The final qualifying work is devoted to the analysis of ways to improve the efficiency of the use of human resources. In the course of the work, a review was made of theoretical material on human resource management; analyzed the size and structure of the organization; the methods of motivation of the organization in question have been studied; staff satisfaction was assessed; analyzed the methods that affect the efficiency of the personnel; recommendations for improving the efficiency of the use of human resources are proposed

Trends in Metal Oxide Stability for Nanorods, Nanotubes, and Surfaces

The formation energies of nanostructures play an important role in determining their properties, including the catalytic activity. For the case of 15 different rutile and 8 different perovskite metal oxides, we find that the density functional theory (DFT) calculated formation energies of (2,2) nanorods, (3,3) nanotubes, and the (110) and (100) surfaces may be described semi-quantitatively by the fraction of metal--oxygen bonds broken and the bonding band centers in the bulk metal oxide