Spinodal decomposition in (CaxBa1-x)(y)Fe4Sb12

Author(s)
Gerda Rogl, Andrij Grytsiv, Matthias Falmbigl, Ernst Bauer, Clemens Mangler, Christian Rentenberger, Michael Zehetbauer, Peter Franz Rogl
Abstract

The thermoelectric and structural properties of a double filled skutterudite solid solution (CaxBa1-x)(y)Fe4Sb12 were investigated. Using X-ray powder and X-ray micro analyses (EPMA) an immiscibility gap was established with a critical point at x approximate to 0.45 and a critical temperature that depends on the filling level (T-C = 590 +/- 5 degrees C at y = 0.8 and T-C = 610 +/- 5 degrees C at y = 0.9). The thermoelectric properties were measured for samples prepared in four different states: (i) a single phase solid solution (CaxBa1-x)(5)Fe4Sb12; (ii) a two phase microcrystalline mixture of CayFe4Sb12 and BayFe4Sb12; (iii) a single phase structure obtained after annealing of the latter sample at 600 degrees C for 200 h; (iv) a spinodally demixed sample after annealing at 400 degrees C for 672 h. The thermoelectric properties of the phase mixture (ii) are compatible with data reported for the microcrystalline end members (CayFe4Sb12 and BayFe4Sb12), whilst the single phase (i and iii) and spinodally decomposed (iv) samples show increased thermopower and decreased thermal conductivity, similarly to those observed for nano-structured CayFe4Sb12 and BayFe4Sb12.

Organisation(s)
Department of Physical Chemistry, Physics of Nanostructured Materials
External organisation(s)
Arizona State University
Journal
Acta Materialia
Volume
60
Pages
4487-4495
No. of pages
9
ISSN
1359-6454
DOI
https://doi.org/10.1016/j.actamat.2012.04.038
Publication date
2012
Peer reviewed
Yes
Austrian Fields of Science 2012
1030 Physics, Astronomy, 104006 Solid state chemistry, 505036 Energy law, 103018 Materials physics
Portal url
https://ucrisportal.univie.ac.at/en/publications/b7aa8f21-8bc2-4e60-bdb2-61a3a87f6c36