Phononic filter effect of rattling phonons in the thermoelectric clathrate Ba${}_8$Ge${}_{40+x}$Ni${}_{6-x}$

Holger Euchner, Stephane Pailhès, Lien Nguyen +6

One of the key requirements for good thermoelectric materials is a low lattice thermal conductivity. Here we present a combined neutron scattering and theoretical investigation of…