Two-band/two-gap superconductivity in carbon-substituted MgB2 evidenced by point-contact spectroscopy -: art. no. 020505

The Andreev reflection measurements of the superconducting energy gap in the carbon-substituted MgB2 are presented. Despite the strong suppression of the transition temperature by 17 K in comparison with the pure MgB2, the same reduced value of the small superconducting energy gap with 2Delta/kT(c)approximate to1.7 has been systematically observed. This indicates that the two-band/two-gap superconductivity is still preserved here.