کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
9841828 | 1525800 | 2005 | 16 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Supercurrents in magnesium diboride/metal composite wire
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
فیزیک و نجوم
فیزیک ماده چگال
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
We have fabricated a series of ex situ copper sheathed powder-in-tube MgB2 wires with 20% by volume Ag, Pb, In, and Ga metal added to the MgB2 powder. We find the transport critical current of these wires increases significantly with the addition of specific metals to the core filament. In particular, the critical current density (JC) of the MgB2/Ga(20%) wire is in excess of 5Â ÃÂ 104Â A/cm2 at 10Â K in self-field, nearly 50 times that of the MgB2/Ag(20%) wire. The temperature dependent JC of all wires is well described as an ensemble of clean S/N/S junctions in which the relevant parameters are the average thickness of the N layer, the critical temperature of the S layer, and a scaling term related to JC at zero temperature. Eliminating the differences in the filament microstructure as the primary cause of the enhanced JC, we suggest that JC is determined by the magnitude of the proximity effect induced superconductivity in the normal metal layer, which is known to be proportional to the electron-electron interaction in N. We present one-dimensional material specific calculations that support this, and zero-field cooled DC magnetic susceptibility data that confirm an increased number of well-connected superconducting grains exist in the composite wires that contain metal additions with large electron-electron interactions and long electron mean free paths.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Physica C: Superconductivity and its Applications - Volume 423, Issues 3â4, 15 July 2005, Pages 103-118
Journal: Physica C: Superconductivity and its Applications - Volume 423, Issues 3â4, 15 July 2005, Pages 103-118
نویسندگان
M.J. Holcomb,