Title :
Dynamics of La and Ce filled xFe4Sb12 skutterudite structures
Author :
Koza, M.M. ; Johnson, M.R. ; Viennois, Romain ; Mutka, Hannu ; Girard, Luc ; Ravot, Didier
Author_Institution :
Inst. Laue Langevin, Grenoble
Abstract :
We have applied high-resolution neutron time-of-flight spectroscopy and ab initio lattice dynamics calculations to study the guest dynamics of La and Ce in the filled skutterudite system xFe4 Sb12. Both the experiments and the calculation show that the guest dynamics is governed by collective vibrations, i.e. phonons. Unlike the case of localized rattlers the guest modes reveal dispersive character and a non-trivial Q-dependence of the signal intensity. The rather low-energy of the guest modes is due to their higher mass and weaker bonding with the host network
Keywords :
ab initio calculations; cerium; iron compounds; lanthanum; lattice dynamics; thermal conductivity; time of flight spectra; vibrational modes; Fe4Sb12-Ce; Fe4Sb12-La; ab initio lattice dynamics calculations; collective vibrations; high resolution neutron time-of-flight spectroscopy; nontrivial Q-dependence; phonon vibrations; skutterudite structures; Acoustic scattering; Atom optics; Energy resolution; Glass; Lattices; Neutrons; Optical scattering; Phonons; Thermal conductivity; Thermoelectricity;
Conference_Titel :
Thermoelectrics, 2006. ICT '06. 25th International Conference on
Conference_Location :
Vienna
Print_ISBN :
1-4244-0811-3
Electronic_ISBN :
1094-2734
DOI :
10.1109/ICT.2006.331272
