Lattice-gas model for alkali-metal fullerides: face-centered-cubic structure
Abstract
A lattice-gas model is suggested for describing the ordering phenomena in alkali-metal fullerides of face-centered-cubic structure assuming the electric charge of alkali ions residing in either octahedral or tetrahedral interstitial sites is completely screened by the first-neighbor C_60 molecules. This approximation allows us to derive an effective ion-ion interaction. The van der Waals interaction between the ion and C_60 molecule is characterized by introducing an additional energy at the tetrahedral sites. This model is investigated by using a three-sublattice mean-field approximation and a simple cluster-variation method. The analysis shows a large variety of phase diagrams when changing the site energy parameter.
Keywords
Cite
@article{arxiv.cond-mat/9512001,
title = {Lattice-gas model for alkali-metal fullerides: face-centered-cubic structure},
author = {Laszlo Udvardi and Gyorgy Szabo},
journal= {arXiv preprint arXiv:cond-mat/9512001},
year = {2009}
}
Comments
10 twocolumn pages (REVTEX) including 12 PS figures