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Superconducting properties of MgB$_2$ probed by radiation-induced disordering

A. E. Karkin·V. I. Voronin·T. V. Dyachkova·A. P. Tyutyunnik·V. G. Zubkov·Yu. G. Zainulin·B. N. Goshchitskii
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Abstract

The electrical resistivity $ρ$ and upper critical field $H_{c2}$ were measured in MgB$_2$ disordered by nuclear reactor neutrons. We found that superconducting temperature $T_c$ decreases under irradiation from 40 to 5 K. Despite strong disordering (more than 10 dpa (displacements per atom)), the initial crystal structure is preserved. The residual resistivity $ρ_0$ increases from 0.35 to 2 m$Ω$ cm while $-dH_{c2}/dT$ remains approximately unchanged ($-dH_{c2}/dT \approx 0.5$ T/K), and such behavior may be interpreted as decrease in the density of electronic states.

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A. E. Karkin, V. I. Voronin, T. V. Dyachkova, A. P. Tyutyunnik, V. G. Zubkov, Yu. G. Zainulin, B. N. Goshchitskii. 2001-03-17. Superconducting properties of MgB$_2$ probed by radiation-induced disordering. https://arxiv.org/abs/cond-mat/0103344

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