Abstract
The thermoelectric properties on polycrystalline single (In)
and double filled (Ce, In) skutterudites are characterized
between 300 and 700 K. Powder neutron diffraction measurements
of the skutterudite compositions InxCo4Sb12 (x¼0.05,
0.2) and Ce0.05In0.1Co4Sb12 as a function of temperature
(12–300 K) were carried out, which gives more insight into the
structural data of single and double-filled skutterudites. Results
show that due to the annealing treatment, a Sb deficiency is
detectable and thus verifies defects at the Sb lattice site of the
skutterudite. Furthermore, we show by electron microprobe
analysis that a considerable amount of indium is lost during
synthesis and post-processing for the single indium filled
samples, but not for the double cerium and indium skutterudite
sample. In our experiments, the double-filled skutterudite is
superior to the single-filled skutterudite composition due to a
higher charge carrier density, a comparable lattice thermal
resistivity, and a higher density of states effective mass.
Furthermore, we obtained a significantly higher Einstein
temperature for the double-filled skutterudite composition in
comparison to the single-filled species, which reflects the high
sensitivity due to filling of the void lattice position within the
skutterudite crystal.
