The search for other superconductors in the MgB2 class currently is focussed on Li{1-x}BC, which when hole-doped (concentration x) should be a metal with the potential to be a better superconductor than MgB2. Here we present the calculated phonon spectrum of the parent semiconductor LiBC. The calculated Raman-active modes are in excellent agreement with a recent observation, and comparison of calculated IR-active modes with a recent report provides a prediction of the LO--TO splitting for these four modes, which is small for the B-C bond stretching mode at ~1200 cm^{-1}, but large for clearly resolved modes at 540 cm^{-1} and 620 cm^{-1}.
@article{arxiv.cond-mat/0209256,
title = {Vibrational Modes in LiBC: Theory Compared with Experiment},
author = {J. M. An and H. Rosner and S. Y. Savrasov and W. E. Pickett},
journal= {arXiv preprint arXiv:cond-mat/0209256},
year = {2009}
}
Comments
4 pages, two embedded figures. Physica B (in press)