Superconducting and Normal State Properties of Heavily Hole-Doped   Diamond
  We report measurements of the specific heat, Hall effect, upper critical field and resistivity on bulk, B-doped diamond prepared by reacting amorphous B and graphite under high-pressure/high-temperature conditions. These experiments establish unambiguous evidence for bulk superconductivity and provide a consistent set of materials parameters that favor a conventional, weak coupling electron-phonon interpretation of the superconducting mechanism at high hole doping. 
V. A. Sidorov, E. A. Ekimov, S. M. Stishov, E. D. Bauer, and J. D.   Thompson