We report a first-principles density-functional calculation of the electronic structure and properties of the recently discovered superconducting β-pyrochlore oxide KOs2O6. We find that the electronic structure near the Fermi energy EF is dominated by strongly hybridized Os 5d and O 2p states. A van Hove singularity very close to Ef leads to a relatively large density of states at EF, and the Fermi surface exhibits strong nesting along several directions. These features could provide the scattering processes leading to the observed anomalous temperature dependence of the resistivity and to the rather large specific-heat mass enhancement we obtain from the calculated density of states and the observed specific-heat coefficient. An estimate of Tc within the framework of the BCS theory of superconductivity taking into account the possible effects of spin fluctuations arising from nesting yields the experimental value.
R. Saniz et al., "Electronic structure properties and BCS superconductivity in ß-pyrochlore oxides: KOss2O6," Physical Review B - Condensed Matter and Materials Physics, vol. 70, no. 10, pp. 100505-1-100505-4, American Physical Society (APS), Sep 2004.
The definitive version is available at http://dx.doi.org/10.1103/PhysRevB.70.100505
Keywords and Phrases
Beta Pyrochlore Oxide; Metal Oxide; Unclassified Drug; Chemical Structure; Density; Density Functional Theory; Electronics; Energy; Mathematical Analysis; Superconductor; Temperature Dependence
International Standard Serial Number (ISSN)
Article - Journal
© 2004 American Physical Society (APS), All rights reserved.