Phonons in A3C60 Lattice and Structural Dynamics
Author
Source
Advances in Condensed Matter Physics
Issue
Vol. 2010, Issue 2010 (31 Dec. 2010), pp.1-6, 6 p.
Publisher
Hindawi Publishing Corporation
Publication Date
2009-12-13
Country of Publication
Egypt
No. of Pages
6
Main Subjects
Abstract EN
The critical temperature (TC) of superconductivity in A3C60 compounds is generally lower smaller with alkali atoms (A).
Furthermore TC decreases with applied pressure.
In the BCS model, these trends are explained by the lower density of states at the Fermi level for a decreased lattice constant (R).
There is more than one counterexample, however, suggesting that BCS does not give the whole truth.
The most important one is that the compound with the largest lattice constant, Cs3C60, is not superconducting at all at ambient pressure.
In this paper we derive a novel model where a negative lattice contribution to Hubbard U, proportional to 1/R, is taken into account.
It is possible to explain why A3C60 compounds with A = Li, and Na have a low TC or are not superconducting at all, and why Cs3C60 is superconducting only at applied pressure and then with the highest TC of all C60 alkali fullerides.
It is concluded that the density of states mechanism derived in the BCS model is in doubt.
Nevertheless superconductivity in A3C60 depends on electron-phonon coupling.
The dominating phonon is the bond stretching Ag phonon, a breathing phonon for the whole fullerene molecular ion.
American Psychological Association (APA)
Larsson, Sven. 2009. Phonons in A3C60 Lattice and Structural Dynamics. Advances in Condensed Matter Physics،Vol. 2010, no. 2010, pp.1-6.
https://search.emarefa.net/detail/BIM-486287
Modern Language Association (MLA)
Larsson, Sven. Phonons in A3C60 Lattice and Structural Dynamics. Advances in Condensed Matter Physics No. 2010 (2010), pp.1-6.
https://search.emarefa.net/detail/BIM-486287
American Medical Association (AMA)
Larsson, Sven. Phonons in A3C60 Lattice and Structural Dynamics. Advances in Condensed Matter Physics. 2009. Vol. 2010, no. 2010, pp.1-6.
https://search.emarefa.net/detail/BIM-486287
Data Type
Journal Articles
Language
English
Notes
Includes bibliographical references
Record ID
BIM-486287