Calculations of electron-phonon coupling are performed for boron-doped diamond structures without electronically compensating defects over a wide range of boron concentration. The effects of boron substitutional disorder are incorporated through the use of randomly generated supercells, leading to a disorder-broadened distribution of results. After averaging over disorder, this study predicts a maximum bulk $T_c$ near $55\mathrm{K}$ for boron concentrations between 20% and 30%, assuming the validity of the simple structural model used and a Coulomb pseudopotential of ${\mu }^{*}=0.12$. Considering only the largest electron-phonon coupling values of the distribution, superconductivity may still percolate through the material at higher temperatures, up to $80\mathrm{K}$, through the regions of large coupling. A synthesis path is proposed to experimentally access this class of materials.

• Received 27 November 2007

DOI:https://doi.org/10.1103/PhysRevB.77.064518