Superconductivity in diamond thin films well above liquid helium temperature

Abstract

We report unambiguous evidence for superconductivity in a heavily boron-doped diamond thin film deposited by microwave plasma assisted chemical vapor deposition (MPCVD) method. An advantage of the MPCVD deposited diamond is that it can contain boron at high concentration, especially in (111) oriented films. Superconducting transition temperatures are determined by transport measurements to be 7.4K for Tc onset and 4.2K for zero resistance. And the upper critical field is estimated to be 7T. Magnetization as a function of magnetic fields shows typical type two superconducting properties.

Superconductivity in polycrystalline diamond thin films

“…Recently, we have succeeded in synthesizing superconducting diamond thin films using the MPCVD method. The onset of the superconducting transition is found to be 8.7K, and zero resistance is obtained at 5.0K (10). The superconducting transition temperature is significantly higher than that reported for HPHT diamond (7).…”

Electronic structures and mechanical properties of boron and boron-rich crystals (Part I)

“…Since then, the superconductivity has been discovered in heavily doped diamond, which was first synthesized at high pressure [6]. This opens a new stream of superconducting research in heavily doped semiconductors [7][8][9].…”

Angle-resolved photoemission study of Si electronic structure: Boron concentration dependence

“…Recently, superconductivity below T c ∼ 0.35 K was reported in Si doped with 6-8 % boron [1] and T c ∼ 1.4 K in SiC doped with 1-2% boron [2], following the observation of superconductivity in heavily boron-doped diamond [3,4]. These observations have aroused much interest in changes in the electronic structures through the metal-insulator (MI) transition induced by the impurity doping for such fundamental materials.…”