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Two band/two gap superconductivity in carbon-substituted MgB2 evidenced by point-contact spectroscopy

P. Samuely·Z. Holanova·P. Szabo·J. Kacmarcik·R. A. Ribeiro·S. L. Bud'ko·P. C. Canfield
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Abstract

The Andreev reflection measurements of the superconducting energy gap in the carbon-substituted MgB$_2$ are presented. Despite the strong suppression of the transition temperature by 17 K in comparison with the pure MgB$_2$, the same reduced value of the small superconducting energy gap with $2Δ/kT_c \approx$ 1.7 has been systematically observed. This indicates that the two band/two gap superconductivity is still preserved here.

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P. Samuely, Z. Holanova, P. Szabo, J. Kacmarcik, R. A. Ribeiro, S. L. Bud'ko, P. C. Canfield. 2003-03-31. Two band/two gap superconductivity in carbon-substituted MgB2 evidenced by point-contact spectroscopy. https://doi.org/10.1103/physrevb.68.020505

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