Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published November 16, 2015 | public
Journal Article

Inelastic neutron scattering study of the lattice dynamics in the clathrate compound BaGe_5

Abstract

We report inelastic neutron scattering (INS) measurements on the polycrystalline oP60-type clathrate BaGe_5, whose crystal structure is related to the type-I clathrate Ba8Ge_(43□3) and to the cP124-clathrate Ba_6Ge_(25). Our results show that BaGe_5 exhibits a similar phonon density of states (PDOS) in the energy range 0–40 meV with respect to Ba8Ge_(43□3). The low-energy region of the PDOS spectrum (0–10 meV) consists of two peaks at 4.1 and 6.2 meV likely related to Ba-weighted modes. Compared to Ba8Ge_(43□3), the low-energy region of the phonon spectrum of BaGe_5 shows a more complex structure, likely reflecting the presence of three distinct crystallographic sites for Ba. The specific heat data of BaGe_5, reexamined in light of the INS results, indicate that the Ba-weighted modes dominate the low-temperature behavior of C_p.

Additional Information

© 2015 IOP Publishing Ltd. Received 3 August 2015, revised 2 October 2015. Accepted for publication 21 October 2015. Published 16 November 2015. The authors thank Petra Scheppan, Renate Hempel-Weber and members of the Kompetenzgruppe Struktur for providing experimental support. C.C. acknowledges the financial support of the CNRS-MPG program. M B and Yu G gratefully acknowledge financial support by the Deutsche Forschungsgemeinschaft (SPP 1415, 'Kristalline Nichtgleichgewichtsphasen (KNG)—Präparation, Charakterisierung und in situ-Untersuchung der Bildungsmechanismen').

Additional details

Created:
August 20, 2023
Modified:
October 25, 2023