Workers in Russia and Los Alamos, USA report in Nature1 superconductivity in boron-doped diamond synthesized at high pressure (nearly 100,000 atmospheres) and temperature (2500-2800 K). Electrical resistivity, magnetic susceptibility, specific heat and field-dependent resistance measurements show that boron-doped diamond (carbon) is a bulk, type-II superconductor below the superconducting transition temperature T_c 4 K.

Boron has one less electron than carbon and, because of its small atomic radius, is relatively easily incorporated into diamond. The boron acts as a charge acceptor and the resulting diamond is effectively hole-doped.

• 1. Superconductivity in diamond,
  Ekimov, E. A., Sidorov V. A., Bauer E. D., Mel'nik N. N., Curro N. J., Thompson J. D., and Stishov S. M.
  , Nature, 4/2004, Volume 428, Issue 6982, p.542 - 545, (2004)