title: Einstein oscillators in thallium filled antimony skutterudites.
abstract: Inelastic neutron scattering measurements on several Tl filled skutterudites (Tl0.5Co3.5Fe0.5Sb12, Tl0.8Co3FeSb12, and Tl0.8Co4Sb11Sn) all show a sharp peak in the vibrational density of states at 57+/-2 K, which is absent in the unfilled skutterudite CoSb3. Heat capacity measurements on Tl0.8Co4Sb11Sn as compared to CoSb3 are consistent with the presence of a localized vibrational mode associated with the "rattling" thallium atoms in this filled skutterudite compound. Both results are well described by a localized Einstein mode model with an Einstein temperature Theta(E) of 53+/-1 K. These data provide perhaps the clearest example of local mode behavior in a concentrated metallic system.
authors.affiliation: Department of Physics, B5, University of Liège, B-4000 Sart-Tilman, Belgium.
authors.forename: Raphaël P
authors.initials: RP
authors.lastname: Hermann
authors.forename: Rongying
authors.initials: R
authors.lastname: Jin
authors.forename: Werner
authors.initials: W
authors.lastname: Schweika
authors.forename: Fernande
authors.initials: F
authors.lastname: Grandjean
authors.forename: David
authors.initials: D
authors.lastname: Mandrus
authors.forename: Brian C
authors.initials: BC
authors.lastname: Sales
authors.forename: Gary J
authors.initials: GJ
authors.lastname: Long