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The pair-breaking critical current density of magnesium diboride

Milind N. Kunchur·Sung-Ik Lee·W. N. Kang
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Abstract

The pair-breaking critical current density j_{d} of magnesium diboride was determined over its entire temperature range by a pulsed dc transport measurement. At fixed low values of current density j, the resistive transition temperature Tc shifts in the classic ΔT_{C}(j)/T_{C}(0) \propto -[j/j_{d}(0)]^{2/3} manner, with a projected j_{d}(0) \approx 2 \times 10^{7}$ A/cm^{2}. The directly measured j_{d}(0), from current-voltage ($I$-$V$)curves at different fixed temperatures, has a similar value and the overall temperature dependence j_{d}(T) and magnitude are consistent with Ginzburg-Landau theory. Keywords: pair, breaking, depairing, superconductor, superconductivity, flux, fluxon, vortex, mgb2

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Milind N. Kunchur, Sung-Ik Lee, W. N. Kang. 2002-12-05. The pair-breaking critical current density of magnesium diboride. https://doi.org/10.1103/physrevb.68.064516

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