Pressure effect of superconducting transition temperature for boron-doped diamond films

Abstract

The superconducting transition temperature of homoepitaxial boron-doped diamond thin films fabricated by microwave plasma-assisted chemical vapor deposition technique depend on substrate orientation. In addition, heavily doped diamond thin films indicate anisotropic lattice expansion. From these points of view, pressure effect will give us knowledge of the superconducting mechanism of boron-doped diamond. We report measurements of the electrical resistivity of heavily boron-doped diamond thin film under pressure up to P = 1.45 GPa and 1.27 GPa for (1 1 1) and (1 0 0) homoepitaxial thin films, respectively. The superconducting transition temperature decreases linearly with increasing pressure by a rate of δ T c/δ P = −1.17 × 10 −1 K/GPa and −1.51 × 10 −2 K/GPa for (1 1 1) and (1 0 0) thin film, respectively.