Berlin 2018 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 5: f-Electron Systems and Heavy Fermions I

TT 5.11: Vortrag

Montag, 12. März 2018, 12:30–12:45, H 3005

Optical response of Cerium-based clathrates — Farzaneh Zamani¹, •Stefan Kirchner², and Silke Paschen³ — ¹Physikalisches Institut and Bethe Center for Theoretical Physics, Universität Bonn, Germany — ²Center for Correlated Matter, Zhejiang University, Hangzhou, Zhejiang 310058, China — ³Institute of Solid State Physics, Vienna University of Technology, Wiedner Hauptstraße 8-10, 1040 Vienna, Austria

Clathrates are a class of caged compounds that display a wide range of physical properties as a function of host-guest composition. Cerium-based type-I clathrates are of particular interest due to their unusual thermoelectric properties with potential for application[1]. The origin of the observed thermopower enhancement at comparatively high temperature in CeBa₇Au₆Si₄₀, however, is still a matter of debate. While Kondo scattering does occur in the system, Curie-Weiss behavior prevails down to about 1K. In order to understand the role of the rattling modes in the thermopower enhancement we address the optical response of CeBa₇Au₆Si₄₀. In particular, we investigate if a model of phonon-enhanced Kondo scattering can explain the differences observed [2] in the optical conductivity of CeBa₇Au₆Si₄₀ and its rare-earth free reference compound.
A. Prokofiev et al.,Nature Mat. 12, 1096-1101 (2013).
G. Johnstone et al., unpublished.