Superconductivity in polycrystalline diamond thin films

Abstract

Superconductivity was discovered in heavily boron-doped diamond thin films deposited by the microwave plasma assisted chemical vapor deposition (MPCVD) method. Advantages of the MPCVD deposited diamond are the controllability of boron concentration in a wide range, and a high boron concentration, especially in (111) oriented films, compared to that of the high-pressure high-temperature method. The superconducting transition temperatures are determined to be 8.7 K for T c onset and 5.0 K for zero resistance by transport measurements. And the upper critical field is estimated to be around 7 T.