Abstract
The electronic structure, lattice dynamics, and the electron-phonon coupling (EPC) in hole -doped and electron -doped diamonds have been extensively investigated using ab initio methods with the virtual crystal approximation. The calculations of -doped diamond correctly reproduced all the essential properties of B-doped diamond such as the increase of lattice constant and the redshift of the Raman spectrum with increasing dopant concentration, and the pressure-induced decrease of . The analysis of the spectral function for -type diamond has shown that optical phonon modes dominate the EPC. From the theoretical prediction of -doped diamond, it is indicated that the metallic -doped diamond might be a good superconductor. It is found that the in -doped diamond increases with the dopant concentration, resulting from the softening of optical phonon modes and the increase of density of states at Fermi level. At a doping level , the in -doped diamond is higher than that in -doped diamond. Phonon linewidth and frozen phonon calculations in -doped diamond suggested that the longitudinal optical phonon mode contributes mainly to the EPC. The possible mechanism of the predicted superconductivity in -doped diamond has been discussed.
2 More- Received 31 January 2005
DOI:https://doi.org/10.1103/PhysRevB.72.014306
©2005 American Physical Society