Vibrational Dynamics of Filled Skutterudites LaT sub( 4)X sub( 12) (T = Fe, Ru, Os, X = As, Sb)

We report on the vibrational properties of the lanthanum filled skutterudite compounds LaRu...Sb..., LaOs...Sb..., and LaOs...As... studied by inelastic neutron scattering. The experimental data are backed up by ab initio lattice dynamics calculations of the complete series of lanthanum filled skutterudites La\(T_{4}X_{12}\) with \(T\) = Fe, Ru, Os and \(X\) = As, Sb. We present details of their structural properties, phonon dispersion relations, vibrational densities of states Z(...) and specific heats \(C_{V}(T)\) calculated from Z(...) within the harmonic approximation. Powder averaged lattice dynamics (PALD) technique is applied to approximate the experimental signal presented as the generalized density of states G(...) with high accuracy. Furthermore, the PALD approach is exploited to compute average transverse \(v_{\text{t}} super({\text{PALD})}\) and longitudinal \(v_{\text{l}} super({\text{PALD})}\) sound velocities, elastic constants \(c_{11} super({\text{PALD})}\), \(c_{44} super({\text{PALD})}\), bulk moduli \(B super({\text{PALD})}\), and Debye temperatures ... The PALD results are compared with data computed from ab initio lattice dynamics calculations. All calculated properties are in very good agreement with literature data. (ProQuest: ... denotes formulae/symbols omitted.)