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in subjects: "Copper Oxides"  
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The surface chemistry of Cu in the presence of CO2 and H2O

Description: The chemical nature of copper and copper oxide (Cu{sub 2}O) surfaces in the presence of CO{sub 2} and H{sub 2}O at room temperature was investigated using ambient pressure x-ray photoelectron spectroscopy. The studies reveal that in the presence of 0.1 torr CO{sub 2} several species form on the initially clean Cu, including carbonate CO{sub 3}{sup 2}, CO{sub 2}{sup {delta}-} and C{sup 0}, while no modifications occur on an oxidized surface. The addition of 0.1 ML Zn to the Cu results in the com… more
Date: July 16, 2008
Creator: Deng, Xingyi; Verdaguer, Albert; Herranz, Tirma; Weis, Christoph; Bluhm, Hendrik & Salmeron, Miquel
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Partner: UNT Libraries Government Documents Department
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Crystal Growth And Characterization of the Model High-Temperature Superconductor HgBa{sub 2}CuO{sub 4+{delta}}

Description: Since the discovery of high-transition-temperature (T{sub c}) superconductivity in La{sub 2-x}Ba{sub x}CuO{sub 4} in 1986, the study of the lamellar copper oxides has remained at the forefront of condensed matter physics. Apart from their unusually high values of T{sub c}, these materials also exhibit a variety of complex phenomena and phases. This rich behavior is a consequence of the lamellar crystal structures, formed of copper-oxygen sheets separated by charge reservoir layers, and of the s… more
Date: March 16, 2007
Creator: Zhao, Xudong; Yu, Guichuan; Cho, Yong-Chan; Chabot-Couture, Guillaume; Barisic, Neven; Bourges, Philippe et al.
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Partner: UNT Libraries Government Documents Department
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Practical superconductor development for electrical power applications - quarterly report for the period ending June 30, 2003.

Description: This is a multiyear experimental research program that focuses on improving relevant material properties of high-critical temperature (T{sub c}) superconductors and developing fabrication methods that can be transferred to industry for production of commercial conductors. The development of teaming relationships through agreements with industrial partners is a key element of the Argonne National Laboratory (ANL) program. A transport critical current density (J{sub c}) of 1.2 x 10{sup 6} A/cm{su… more
Date: September 16, 2003
Creator: Dorris, S. E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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What is the symmetry of the high T{sub c} order parameter?

Description: In recent years, there has been a raging controversy regarding the orbital symmetry of the superconducting order parameter (OP) in the high temperature superconductors. Many experiments were interpreted in terms of a d{sub x{sup 2}-y{sup 2}}-wave OP, but many others were interpreted in terms of a more conventional s-wave OP. We review the problems of both intrinsic and extrinsic natures with the phase-sensitive experiments on YBCO. The authors further show that the photoemission experiments of … more
Date: April 16, 1998
Creator: Klemm, R. A.
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Partner: UNT Libraries Government Documents Department
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Recent neutron scattering results on high-temperature superconductors

Description: Triple-axis spectrometry has been used to determine the magnetic excitations in YBa{sub 2}Cu{sub 3}O{sub 7}. Polarized measurements at 100 K show the scattering consists of a peak near 40 meV superposed on a small relatively flat background. The 40-meV peak is found to be sharp in energy and anisotropic in momentum occupying a square portion of the Cu-O reciprocal lattice plane. The temperature dependence of the scattering is identical at the square side and corner. Polarized measurements show … more
Date: September 16, 1994
Creator: Mook, H. A.; Dai, P.; Aeppli, G.; Mason, T. E.; Hecker, N. E.; Harvey, J. A. et al.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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MAGNETIC EXCITATIONS AND DOUBLE GAP IN THE S=1/2 LINEAR CHAIN QUANTUM ANTIFERROMAGNET BaCu{sub 2}Si{sub 2}O{sub 7}

Description: The magnetic excitation spectrum of the ideal S=1/2 1-dimensional quantum antiferromagnet (AF), contains no single-mode contributions, and, in fact, can be described as a 2-particle continuum of spinons. Chain-MF theory predicts that a weakly coupled chains system becomes ordered at low temperatures. In the ordered state a sharp magnon excitation is present. The continuum persists, but is separated from the magnon branch by an appreciable energy gap. On the other hand, if weakly coupled chains … more
Date: March 16, 2000
Creator: Raymond, S.; Zheludev, A.; Masuda, T.; Kakurai, K.; Ressouche, E. & Wildes, A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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