Diamond
Superconductivity in diamond was achieved through heavy p-type doping by boron such that the individual doping atoms started interacting and formed an "impurity band". The superconductivity was of type-II with the critical temperature Tc = 4 K and critical magnetic field Hc = 4 T. Later, Tc ~ 11K has been achieved in homoepitaxial CVD films.
Regarding the origin of superconductivity in diamond, three alternative theories exist at the moment: conventional BCS theory based on phonon-mediated pairing, correlated impurity band theory and spin-flip-driven pairing of holes weakly localized in the vicinity of the Fermi level. Whereas there is no solid experimental support for either model, recent accurate measurements of isotopic shift of the transition temperature Tc upon boron and carbon isotopic substitutions favor the BCS theory.
Read more about this topic: Covalent Superconductor
Famous quotes containing the word diamond:
“A poet who makes use of a worse word instead of a better, because the former fits the rhyme or the measure, though it weakens the sense, is like a jeweller, who cuts a diamond into a brilliant, and diminishes the weight to make it shine more.”
—Horace Walpole (1717–1797)
“The lover never sees personal resemblances in his mistress to her kindred or to others. His friends find in her a likeness to her mother, or her sisters, or to persons not of her blood. The lover sees no resemblance except to summer evenings and diamond mornings, to rainbows and the song of birds.”
—Ralph Waldo Emerson (1803–1882)
“Masts in the offing wagged their tops;
The swinging waves pealed on the shore;
The saffron beach, all diamond drops
And beads of surge, prolonged the roar.”
—John Davidson (1857–1909)