Several experimental and theoretical studies in cobaltates suggest the proximity of the system to charge ordering (CO). We show, qualitatively, in the frame of a t−V model coupled to phonons that optical phonon modes at the K and M points of the Brillouin zone, which involves only O-ions displacement around a Co-ion, are good candidates to display anomalies due to the CO proximity. If by increasing of H2O content the system is pushed closer to CO, the mentioned phonon modes should show softening and broadening.
@article{arxiv.cond-mat/0612358,
title = {Charge order and phonon renormalizations: Possible implications for cobaltates},
author = {M. Bejas and A. Greco and A. Foussats},
journal= {arXiv preprint arXiv:cond-mat/0612358},
year = {2009}
}
Comments
4 pages, 4 figures, accepted for publication in Phys. Rev. B