On unconventional superconductivity in boron-doped diamond

Considering the magnetotransport data obtained on nanocrystalline variety of heavily boron-doped diamond films prepared by plasma-enhanced chemical vapour deposition technique, we have proposed a new model of unconventional superconductivity observed in this material (T-C = 1.66 K) which is based on the very experimental fact that symptoms of localization are precursors to the on-set of superconductivity. It is shown that the system treated as disordered Mott's metal in which the low-temperature transport is controlled by weak localization of carriers should reveal, in the Kelvin range, superconducting transition just when the holes occupying neighbouring weakly localized orbits are paired by means of spin-flip mechanism. Besides, close analogy between properties of a hole on weakly localized orbit and vortex in a classical type-II superconductor is suggested. (c) 2006 Elsevier B.V. All rights reserved.