Superconductivity of nonstoichiometric niobium carbide
Karimov Yu. S. , Utkina T. G.
Heat treatment of niobium carbide alters the state of its carbon sublattice and causes a significant change in the superconducting transition temperature. The electron pairing in this case might be due to an interaction of the conduction electrons with the local modes of tunneling configurations which arise upon a local restructuring of a small group of carbon atoms.