Publications in Scientific Journals:

N. Melnychenkc-Koblyuk, A. Grytsiv, P. Rogl, M. Rotter, R. Lackner, E. Bauer, L. Fornasari, F. Marabelli, G. Giester:
"Structure and physical properties of type-I clathrate solid-solution Ba8PtxGe46−x−y y ( =vacancy)";
Physical Review B, 76 (2007), 195124-1 - 195124-7.

English abstract:
Structure and physical properties of type-I clathrate solid-solution Ba8PtxGe46−x−y y ( =vacancy)

N. Melnychenko-Koblyuk, A. Grytsiv, P. Rogl, and M. Rotter
Institute of Physical Chemistry, University of Vienna, A-1090 Wien, Austria

R. Lackner and E. Bauer
Institute of Solid State Physics, Vienna University of Technology, A-1040 Wien, Austria

L. Fornasari and F. Marabelli
Physics Department "Alessandro Volta," University of Pavia, I-27100 Pavia, Italy

G. Giester
Institute of Mineralogy and Crystallography, University of Vienna, Althanstrasse 14, A-1090 Wien, Austria

(Received 18 July 2007; revised 19 September 2007; published 28 November 2007)

Formation, crystal chemistry, and physical properties were investigated for the solid-solution Ba8PtxGe46−x−y y is a vacancy) deriving from binary clathrate Ba8Ge43[square, open]3 with a solubility limit of ~3.5 Pt atoms/f.u. at T=800 C. Structural investigations throughout the homogeneity region confirm isotypism with the cubic primitive clathrate type-I structure (space group type Pm3n) and lattice parameters ranging from a=1.0657(2) nm for Ba8Ge43 3 to a=1.0752(2) nm for Ba8Pt3.5Ge41.5 1.0. Phase relations for the region concerning the clathrate solution were derived at subsolidus temperatures as well as at 800 C. Transport properties evidence electrons as the majority charge carriers in the system with a slight dependency on the Pt content. The system is located close to a semiconducting regime with a gap in the electronic density of states of a few thousand K. No low temperature maximum is obvious from thermal conductivity which is dominated by the lattice contribution. Thermal conductivity furthermore documents a high efficiency of phonon scattering on vacancies.

"Official" electronic version of the publication (accessed through its Digital Object Identifier - DOI)

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Created from the Publication Database of the Vienna University of Technology.