title: Compositional dependence of the thermoelectric properties of (Sr(x)Ba(x)Yb₁₋₂x)(y)Co₄Sb₁₂ skutterudites.
abstract: High temperature thermoelectric (TE) properties for triple-filled skutterudites (Sr(x)Ba(x)Yb₁₋₂x)(y)Co₄Sb₁₂ were investigated for alloy compositions in two sections of the system: (a) for x = 0.25 with a filling fraction y ranging from 0.1 to 0.25 and (b) for 0 < x < 0.5 and y = 0.11 + 0.259x. The representation of the figure of merit, ZT, as a function of skutterudite composition, defined the compositional range (0.25 < x < 0.4; 0.18 < y < 0.24) with ZT over 1.4 at 800 K. It was shown that an enhanced TE performance for these triple-filled skutterudites is caused by low electrical resistivities and low lattice thermal conductivities, as well as by a fine tuning of the chemical composition. Low temperature measurements for the samples with the highest ZT values showed that even a small change of the filler ratios changes the contribution of scattering effects, the carrier concentration and the mobility.
authors.affiliation: Institute of Physical Chemistry, University of Vienna, Wien, Austria.
authors.forename: G
authors.initials: G
authors.lastname: Rogl
authors.forename: A
authors.initials: A
authors.lastname: Grytsiv
authors.forename: N
authors.initials: N
authors.lastname: Melnychenko-Koblyuk
authors.forename: E
authors.initials: E
authors.lastname: Bauer
authors.forename: S
authors.initials: S
authors.lastname: Laumann
authors.forename: P
authors.initials: P
authors.lastname: Rogl