Metallic Superconductors [7] - MgB2 Wires -
نویسندگان
چکیده
منابع مشابه
Pressure effects on Ca60Al40 metallic glass superconductors
Theoretical computation of the pressure dependence superconducting state parameters of binary Ca60Al40 is reported using model potential formalism. Explicit expressions have been derived for the volume dependence of the electron–phonon coupling strength λ and the Coulomb pseudopotential μ* considering the variation of Fermi momentum KF and Debye temperature ӨD with volume. Well known Ashcroft’s...
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The phases in Cu sheathed MgB2 wires fabricated using very short annealing time are studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), and critical current (Ic) measurements. By comparison with the XRD pattern of our synthesized MgCu2, the XRD line located at 2h 36.1 for all Cu-sheathed MgB2 wire samples is unambiguously identified to be due to the MgCu2 phase. This line wa...
متن کاملSuperconductivity of metallic boron in MgB2.
Boron in MgB2 forms stacks of honeycomb layers with magnesium as a space filler. Band structure calculations indicate that Mg is substantially ionized, and the bands at the Fermi level derive mainly from B orbitals. Strong bonding with an ionic component and considerable metallic density of states yield a sizable electron-phonon coupling. Together with high phonon frequencies, which we estimate...
متن کاملSuperconductivity of MgB2: covalent bonds driven metallic.
A series of calculations on MgB2 and related isoelectronic systems indicates that the layer of Mg2+ ions lowers the nonbonding B pi ( p(z)) bands relative to the bonding sigma ( sp(x)p(y)) bands compared to graphite, causing sigma-->pi charge transfer and sigma band doping of 0.13 holes/cell. Because of their two dimensionality the sigma bands contribute strongly to the Fermi level density of s...
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ژورنال
عنوان ژورنال: TEION KOGAKU (Journal of the Cryogenic Society of Japan)
سال: 2011
ISSN: 0389-2441,1880-0408
DOI: 10.2221/jcsj.46.53