Type-I clathrate Ba8NixSi46-x: Phase relations, crystal chemistry and thermoelectric properties

Autor(en)
Matthias Falmbigl, Mingxing Chen, Andrij Grytsiv, Peter Franz Rogl, Esmaeil Royanian, Herwig Michor, Ernst Bauer, Raimund Podloucky, Gerald Giester
Abstrakt

The phase relations, crystal structure and thermoelectric properties of the type-I solid solution Ba8NixSi46-x were investigated. Based on X-ray diffraction, differential thermal analysis and electron probe microanalysis data, a partial phase diagram was constructed for the Si-rich part of ternary system Ba-Ni-Si at 800 °C. The solubility range of Ni in the clathrate-I phase at 800 °C was determined (2.9 = x = 3.8) and thermoelectric properties, namely electrical resistivity, Seebeck-coefficient and thermal conductivity, were measured in the temperature range from 300 to 850 K. A shift of the thermoelectric properties from a predominantly metallic to a more semiconducting behavior was observed for an increasing Ni-content. Density functional calculations revealed a significant decrease of the gap width in the density of states induced by the incorporation of Ni. Electrical resistivity and Seebeck coefficients for Ba8NixSi46-x with 3.3 = x = 3.8 have been modeled within the rigid band approximation.

Organisation(en)
Institut für Physikalische Chemie, Institut für Mineralogie und Kristallographie
Externe Organisation(en)
Technische Universität Wien
Journal
Dalton Transactions
Band
41
Seiten
8839-8849
Anzahl der Seiten
11
ISSN
1477-9226
DOI
https://doi.org/10.1039/c2dt30279a
Publikationsdatum
2012
Peer-reviewed
Ja
ÖFOS 2012
104017 Physikalische Chemie, 105113 Kristallographie
Link zum Portal
https://ucrisportal.univie.ac.at/de/publications/2005eb85-9bc7-4f5e-b926-72e444de7f62