Vibrational modes in silicon clathrate compounds : a key to understanding superconductivity
Langue
en
Article de revue
Ce document a été publié dans
Physical Review B: Condensed Matter and Materials Physics (1998-2015). 2002, vol. 66, n° 1, p. 014532 (7 p.)
American Physical Society
Résumé en anglais
Several doped type-I silicon clathrates (Na8@Si46, K8@Si46, Ba8@Si46 and I8@Si46) have been investigated both experimentally by inelastic neutron scattering and x-ray-absorption spectroscopy and theoretically by ab initio ...Lire la suite >
Several doped type-I silicon clathrates (Na8@Si46, K8@Si46, Ba8@Si46 and I8@Si46) have been investigated both experimentally by inelastic neutron scattering and x-ray-absorption spectroscopy and theoretically by ab initio calculations. We find that Ba atoms have a stronger coupling with the host lattice than Na or K ones. We show that in the superconductor Ba8@Si46 the coupling is effectively done by host acoustic phonons exciting guest acoustic modes. These features suggest that the host-guest vibrational coupling is a crucial parameter to explain the appearance of superconductivity in addition to the density of states near the Fermi level.< Réduire
Mots clés en anglais
Silicon
Clathrate
Superconductivity
Origine
Importé de halUnités de recherche