LiBC, a semiconducting ternary borocarbide constituted of the lightest elements only, has been synthesized and characterized by x-ray powder diffraction, dielectric spectroscopy, and conductivity measurements. Utilizing an infrared microscope the phonon spectrum has been investigated in single crystals. The in-plane B-C stretching mode has been detected at 150 meV, noticeably higher than in AlB2, a non-superconducting isostructural analog of MgB2. It is this stretching mode, which reveals a strong electron-phonon coupling in MgB2, driving it into a superconducting state below 40 K, and is believed to mediate predicted high-temperature superconductivity in hole-doped LiBC [H. Rosner, A. Kitaigorodsky, and W. E. Pickett, Phys. Rev. Lett. 88, 127001 (2002)].
@article{arxiv.cond-mat/0207299,
title = {Electronic and optical properties of LiBC},
author = {A. V. Pronin and K. Pucher and P. Lunkenheimer and A. Krimmel and A. Loidl},
journal= {arXiv preprint arXiv:cond-mat/0207299},
year = {2009}
}