Lanthanide-Doping of Inorganic Tin Clathrates Grown with Flux*

Thermoelectricity – the ability to convert heat to electricity – has competing mechanisms that determine the effectiveness of a thermoelectric material and one way of enhancing it is to have weakly bound atoms rattling in cages, scattering phonons. Clathrates comprise cavities formed usually by p-block elements in which heavier atoms reside. Rare-earth doping has been shown to enhance the thermopower in clathrates comprising gallium, silicon and germanium. Here we report on the growth and characterization of lanthanide-doped tin-comprising clathrates of the form RExAE8–xGa16Sn30, grown with the Sn-self flux technique.