The lattice dynamical properties of LixBC are calculated for several values of x using density functional perturbation theory. We find that the electron-phonon coupling parameter λ increases monotonically with decreasing x to a maximum value of 1.4 for x=0.125 owing to the increasing radius of multiply-nested Fermi surface cylinders. The B-C bond-stretching phonon modes have frequencies which are 28% higher than the equivalent modes in MgB2. This combination results in a Tc of about 65 K for x=0.5.
@article{arxiv.cond-mat/0210704,
title = {First-principles Calculation of Superconductivity in Hole-doped LiBC: $T_c=65$ K},
author = {J. K. Dewhurst and S. Sharma and C. Ambrosch-Draxl and B. Johansson},
journal= {arXiv preprint arXiv:cond-mat/0210704},
year = {2009}
}