The effect of high pressure on structural and electronic properties of the novel superconductor \MB has been calculated using the full-potential linearized augmented-plane-wave method. Despite the layered crystal structure of \MB nearly isotropic compression (bulk modulus B0=140.1(6) GPa) is found with only a 1.2% decrease of the c/a ratio at 10 GPa. The effect of pressure on the critical temperature has been estimated on the basis of BCS theory and good agreement with experimental data is found. Our results suggest that it is a combination of increasing phonon frequency and decreasing electronic density of states at the Fermi level which leads to the observed decrease of the critical temperature under pressure.
@article{arxiv.cond-mat/0102462,
title = {Calculated elastic and electronic properties of MgB$_2$ at high pressures},
author = {I. Loa and K. Syassen},
journal= {arXiv preprint arXiv:cond-mat/0102462},
year = {2009}
}
Comments
10 pages, 3 figures (EPS), Elsevier LaTeX. More detailed analysis of the pressure dependence of Tc; results unchanged. Manuscript accepted for publication in Solid State Commun