Superhard superconducting materials based on diamond and cubic boron nitride

Abstract
Superhard superconducting samples with a critical temperature of T c = 12.6 K are obtained when synthetic diamond powders that were preliminarily coated with a niobium film are sintered at a pressure of 7.7 GPa and a temperature of 1973 K. Superhard superconductors with T c = 9.3 K are obtained when diamond and molybdenum powders are sintered at a pressure of 7.7 GPa and a temperature of 2173 K. Superconducting samples with T c = 36.1–37.5 K have been obtained in the systems diamond-MgB2 and cubic boron nitride-MgB2.