Current Search: High temperature superconductors (x)
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Title
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The effects of the chelating agents on the 123-superconductor.
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Creator
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Zhuang, Huifang, Florida Atlantic University, Carraher, Charles E.
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Abstract/Description
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This study reports the initial evaluation of the effect of selected chelating agents on the 123-superconductor. For the chelating agents oxalic acid and disodium oxalate, the extent and the rate of magnetic susceptibility decrease are discussed with respect to their concentration, site of chelation, exposure time and selectivity. The magnetic susceptibility measurements were carried out with a Superconductor Characterization Cryostat and the surface analysis was accomplished by employing...
Show moreThis study reports the initial evaluation of the effect of selected chelating agents on the 123-superconductor. For the chelating agents oxalic acid and disodium oxalate, the extent and the rate of magnetic susceptibility decrease are discussed with respect to their concentration, site of chelation, exposure time and selectivity. The magnetic susceptibility measurements were carried out with a Superconductor Characterization Cryostat and the surface analysis was accomplished by employing Auger Electron Spectroscopy (AES) and X-Ray Photoelectron Spectroscopy (XPS). The results show that the solution containing oxalic acid can remove copper atoms from the superconductor surface. The extent and the rate of superconductivity decrease can be controlled by changes in concentration, addition sequence and exposure time.
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Date Issued
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1990
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PURL
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http://purl.flvc.org/fcla/dt/14627
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Subject Headings
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High temperature superconductors, Chelates
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Format
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Document (PDF)
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Title
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Experimental studies of yttrium barium(2)(copper(1-x)iron(x))(3)oxygen(7+delta) and bismuth(2)strontium(2)calcium(n-1)copper(n)oxygen(2n+4) high T(c) superconductors.
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Creator
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Lu, Huizong, Florida Atlantic University, Medina, Fernando D.
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Abstract/Description
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Fe-substituted Y123 and Bi-based high Tc superconducting samples were prepared and studied. Magnetic susceptibility measurements, x-ray diffraction and Scanning Electron Microscopy were used to study the transition temperature Tc, preferential grain orientation and phase formation of the compounds. Tc was found to decrease more rapidly with Fe concentrations above 2.5%. Thermally reducing the oxygen content shows that Fe clusters form at high Fe concentrations. Magnetic susceptibility and x...
Show moreFe-substituted Y123 and Bi-based high Tc superconducting samples were prepared and studied. Magnetic susceptibility measurements, x-ray diffraction and Scanning Electron Microscopy were used to study the transition temperature Tc, preferential grain orientation and phase formation of the compounds. Tc was found to decrease more rapidly with Fe concentrations above 2.5%. Thermally reducing the oxygen content shows that Fe clusters form at high Fe concentrations. Magnetic susceptibility and x-ray diffraction measurements show that only the 80 K phase is present in Bi4Sr3Ca3Cu6Ox samples. For Bi0.7Pb0.3SrCaCu1.8Ox and Bi1.8Pb0.2Sr2Ca2Cu3Ox samples, the 110 K phase becomes dominant after sintering for 126 hours and 48 hours respectively. Preferential grain orientation was also observed in these materials.
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Date Issued
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1990
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PURL
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http://purl.flvc.org/fcla/dt/14643
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Subject Headings
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High temperature superconductivity, High temperature superconductors
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Format
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Document (PDF)